JP7501001B2 - Vehicle air conditioning system - Google Patents

Description

The present invention relates to a vehicle air conditioner with a cooling function that cools an object to be cooled.

Conventionally, as a technology related to a vehicle air conditioner with a cooling function, for example, the technology described in Patent Document 1 is known. In the refrigeration cycle device of the vehicle air conditioner of Patent Document 1, an air conditioning evaporator section and a cooling heat exchange section are arranged in parallel. Therefore, according to Patent Document 1, it is possible to realize cooling using the air conditioning evaporator section and cooling of the battery via the cooling heat exchange section and the battery cooling circuit.

The vehicle air conditioning system of Patent Document 1 also includes a cooling flow passage section through which the refrigerant flows to the cooling heat exchange section, and a cooling on-off valve (i.e., a battery solenoid valve) that opens and closes the cooling flow passage section.

JP 2014-235897 A

In the vehicle air conditioning system of Patent Document 1, it is presumed that a fixed throttle is used as the cooling pressure reduction section that reduces the pressure of the refrigerant flowing into the cooling heat exchange section. For this reason, the cycle efficiency (COP) of the refrigeration cycle device is worse than when a variable throttle is used as the cooling pressure reduction section.

For this reason, in vehicle air conditioning systems with a cooling function, it is desirable to use an electric expansion valve as the cooling pressure reducing section. In this case, it is necessary to consider the opening degree of the electric expansion valve when battery cooling is not required.

For example, when cooling of the battery is not required, it is possible to close the cooling on-off valve and the electric expansion valve. However, according to detailed studies by the present applicant, in this example, the refrigerant may become trapped between the cooling on-off valve and the electric expansion valve, and the pressure in the cooling flow passage may increase as the temperature of the trapped refrigerant increases.

In view of the above, the present invention aims to suppress the pressure rise in the refrigerant flow path when cooling of the object to be cooled is not required.

In order to achieve the above object, the vehicle air conditioner according to claim 1 comprises:
A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) for radiating heat from a refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) for reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates a refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
a cooling flow passage section (460) through which a refrigerant flows from the branch section to a cooling pressure reducing section;
An opening/closing portion (14b) for opening and closing the cooling flow path portion;
A control unit (50) for controlling the operation of the cooling pressure reducing unit and the opening and closing unit,
The control unit closes the opening/closing unit and opens the cooling pressure reducing unit to an extent that allows the refrigerant to pass through when there is no request to cool the object to be cooled ;
The refrigerant contains refrigeration oil.
When starting to cool the air for air conditioning in the air conditioning evaporator, an oil recovery control is executed to return refrigeration oil remaining in at least one of the air conditioning evaporator and the cooling evaporator to the compressor;
a cooling flow rate adjusting section (18a, 18b) for adjusting the flow rate of a refrigerant flowing into the cooling evaporation section;
a cooling flow rate control unit (50a) for controlling the operation of the cooling flow rate adjustment unit;
the cooling flow rate control unit controls the operation of the cooling flow rate adjustment unit so that an increase in the throttle opening of the cooling flow rate adjustment unit per unit time is equal to or less than a predetermined reference increase amount when the refrigerant is caused to flow into the cooling evaporation unit;
A limit opening determination unit (S412) is provided for determining a limit opening (LDop) which is an upper limit of the throttle opening of the cooling flow rate adjustment unit,
The cooling flow rate control section controls the operation of the cooling flow rate adjustment section so that the throttle opening of the cooling flow rate adjustment section is equal to or smaller than the limit opening when the refrigerant is caused to flow into the cooling evaporation section.
The vehicle air conditioner according to claim 2 further comprises:
A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) for radiating heat from a refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) for reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates a refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
a cooling flow passage section (460) through which a refrigerant flows from the branch section to a cooling pressure reducing section;
An opening/closing portion (14b) for opening and closing the cooling flow path portion;
A control unit (50) for controlling the operation of the cooling pressure reducing unit and the opening and closing unit,
When there is no request to cool the object to be cooled, the control unit closes the opening/closing unit and opens the cooling pressure reducing unit to an opening degree that allows the refrigerant to pass through;
The refrigerant contains refrigeration oil.
When starting to cool the air for air conditioning in the air conditioning evaporator, an oil recovery control is executed to return refrigeration oil remaining in at least one of the air conditioning evaporator and the cooling evaporator to the compressor;
An upper limit value determination unit (S303) is provided for determining an upper limit value of a refrigerant discharge capacity of the compressor;
The upper limit value determination unit determines the upper limit value when oil recovery control is executed to a value higher than the upper limit value in an operating mode in which refrigerant is allowed to flow into the air conditioning evaporator and is prohibited from flowing into the cooling evaporator.
The vehicle air conditioner according to claim 3 further comprises:
A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) for radiating heat from a refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) for reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates a refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to thereby cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
a cooling flow passage section (460) through which a refrigerant flows from the branch section to a cooling pressure reducing section;
An opening/closing portion (14b) for opening and closing the cooling flow path portion;
A control unit (50) for controlling the operation of the cooling pressure reducing unit and the opening and closing unit,
When there is no request to cool the object to be cooled, the control unit closes the opening/closing unit and opens the cooling pressure reducing unit to an opening degree that allows the refrigerant to pass through;
The refrigerant contains refrigeration oil.
When starting to cool the air for air conditioning in the air conditioning evaporator, an oil recovery control is executed to return refrigeration oil remaining in at least one of the air conditioning evaporator and the cooling evaporator to the compressor;
The oil recovery control is prohibited when the temperature (TEBR, TEBL) of the cooling evaporator becomes equal to or lower than a predetermined reference frost temperature (KTEB1, KTEB3).
The reference frost temperature (KTEB1) used when the oil recovery control is being executed is set to a temperature lower than the reference frost temperature (KTEB3) used when the oil recovery control is not being executed.

This prevents the opening/closing section (14b) and the cooling pressure reduction section (18a, 18b) from being closed at the same time. This makes it possible to suppress the pressure in the cooling flow passage section (460) from increasing due to an increase in the temperature of the refrigerant trapped between the opening/closing section (14b) and the cooling pressure reduction section (18a, 18b).

Note that the symbols in parentheses for each means described in this section and in the claims indicate the corresponding relationship with the specific means described in the embodiments described below.

1 is a schematic diagram of a vehicle to which an air conditioning device for a vehicle according to an embodiment is applied; 1 is an overall configuration diagram of a vehicle air conditioning device according to an embodiment; 2 is a block diagram showing an electric control unit of the vehicle air conditioner according to the embodiment; FIG. 4 is a flowchart showing a control process of automatic air conditioning control of the vehicle air conditioner according to the embodiment. 4 is a control characteristic diagram for determining an air volume of an air conditioner blower in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a flowchart showing a part of a control process of the vehicle air conditioner according to the embodiment. 4 is a control characteristic diagram for determining an operation state of a water heater in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a control characteristic diagram for determining a target heat medium temperature in a control process of the vehicle air conditioner according to the embodiment; FIG. 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 4 is a table showing air conditioning battery requirements in a control process of the vehicle air conditioner according to one embodiment; 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 5 is a flowchart illustrating another part of the control process of the vehicle air conditioner according to the embodiment. 4 is a table showing whether or not a battery cooling operation is performed in a control process of an air conditioner for a vehicle according to an embodiment; 5 is a control characteristic diagram for determining an evaporator temperature determination value f2 in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a table showing a correction value β1 in a control process of the vehicle air conditioner according to the embodiment; 10 is a table showing a hysteresis β2 in the control process of the vehicle air conditioner according to the embodiment; 4 is a control characteristic diagram for determining an inside air temperature determination value f1 in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a table showing a correction value α1 in a control process of the vehicle air conditioner according to the embodiment; 5 is a control characteristic diagram for determining an elapsed time determination value f3 in the control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a table showing a reference elapsed time TIMER in a control process of the vehicle air conditioner according to the embodiment; 4 is a control characteristic diagram for determining a time limit LTop in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a control characteristic diagram for determining a limit opening degree LDop in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a control characteristic diagram for determining an operating rate of an outside air fan in a control process of the vehicle air conditioner according to the embodiment; FIG. 4 is a flowchart showing a control process for oil recovery control of the vehicle air conditioner according to the embodiment; 4 is a table showing switching of a refrigerant circuit in a refrigeration cycle device of an air conditioner for a vehicle according to one embodiment.

One embodiment of a vehicle air conditioner 1 according to the present invention will be described below with reference to the drawings. The vehicle air conditioner 1 of this embodiment is mounted on an electric vehicle that obtains driving force for running the vehicle from an electric motor. The vehicle air conditioner 1 of this embodiment is a vehicle air conditioner with a cooling function that conditions the interior of the vehicle cabin, which is the space to be air-conditioned, in the electric vehicle, and also cools the battery 70, which is the object to be cooled.

Battery 70 is a secondary battery that stores power to be supplied to on-board devices such as an electric motor. Battery 70 is a battery pack formed by electrically connecting multiple battery cells in series or parallel.

The battery cells are secondary batteries that can be charged and discharged. In this embodiment, lithium ion batteries are used as the battery cells. Each battery cell is formed in a flattened rectangular parallelepiped shape. The battery cells are stacked and integrated so that their flat surfaces face each other. Therefore, the battery 70 as a whole is also formed in a roughly rectangular parallelepiped shape.

This type of battery 70 is prone to a decrease in output at low temperatures and a rapid deterioration at high temperatures. For this reason, the temperature of the battery 70 must be maintained within an appropriate temperature range (in this embodiment, 15°C or higher and 55°C or lower) that allows the battery 70 to exhibit sufficient charging and discharging performance.

Furthermore, in a battery 70 formed by electrically connecting multiple battery cells, if the performance of any one of the battery cells deteriorates, the performance of the entire battery pack will deteriorate. For this reason, when cooling the battery 70, it is desirable to cool all the battery cells evenly.

The vehicle air conditioner 1 of this embodiment includes a refrigeration cycle device 10, a heat medium circuit 20, an interior air conditioning unit 30, a battery pack 40, and an air conditioning control device 50 shown in FIG. 3, as shown in FIG. 1. The up, down, front, and rear arrows in FIG. 1 indicate the up, down, front, and rear directions of the vehicle.

First, the refrigeration cycle device 10 will be described. In the vehicle air conditioner 1, the refrigeration cycle device 10 cools the air conditioning air blown into the vehicle cabin and the cooling air blown onto the battery 70. The refrigeration cycle device 10 can switch between a battery-only cycle, an air conditioning-only cycle, and an air conditioning-battery cycle as a refrigerant circuit.

The air conditioning only cycle is a refrigerant circuit that is switched to when cooling the air for air conditioning without cooling the cooling air. More specifically, the air conditioning only cycle is a refrigerant circuit that flows refrigerant into the air conditioning evaporator 16 described below without flowing refrigerant into the right-side battery evaporator 19a and the left-side battery evaporator 19b described below.

The battery-only cycle is a refrigerant circuit that is switched to cool the cooling air without cooling the air-conditioning air. More specifically, the battery-only cycle is a refrigerant circuit that allows refrigerant to flow into the right-side battery evaporator 19a and the left-side battery evaporator 19b without allowing refrigerant to flow into the air-conditioning evaporator 16.

The air conditioning battery cycle is a refrigerant circuit that can be switched when cooling both the air conditioning air and the cooling air. More specifically, the air conditioning battery cycle is a refrigerant circuit that allows refrigerant to flow into the air conditioning evaporator 16 and also into the right battery evaporator 19a and the left battery evaporator 19b.

The refrigeration cycle device 10 uses an HFO refrigerant (specifically, R1234yf) as the refrigerant. The refrigeration cycle device 10 configures a vapor compression subcritical refrigeration cycle in which the refrigerant pressure on the high-pressure side does not exceed the critical pressure of the refrigerant. Refrigeration oil for lubricating the compressor 11 is mixed into the refrigerant. In this embodiment, PAG oil (polyalkylene glycol oil), which is compatible with liquid-phase refrigerants, is used as the refrigeration oil. A portion of the refrigeration oil circulates through the cycle together with the refrigerant.

The compressor 11 in the refrigeration cycle device 10 draws in, compresses, and discharges the refrigerant. The compressor 11 is disposed in a drive unit room at the front of the vehicle. The drive unit room forms a space in which at least some of the equipment (e.g., electric motor) used to generate or adjust the driving force for running the vehicle is disposed.

The compressor 11 is an electric compressor that uses an electric motor to rotate a fixed-capacity compression mechanism with a fixed discharge capacity. The rotation speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from the air conditioning control device 50.

The refrigerant inlet side of the condenser 12 is connected to the discharge port of the compressor 11. The condenser 12 exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the outside air blown by the outside air fan 12a. The condenser 12 is a condensation radiator that radiates heat contained in the refrigerant to the outside air, condensing the refrigerant. The condenser 12 is located on the front side of the drive unit room.

The outdoor air fan 12a is an electric blower that blows outdoor air toward the condenser 12. The outdoor air fan 12a has its rotation speed (i.e., its blowing capacity) controlled by a control voltage output from the air conditioning control device 50. The outdoor air fan 12a may be a suction type fan or a blowing type fan as long as it can send outdoor air to the condenser 12.

The receiver 12b is connected to the refrigerant outlet side of the condenser 12. The receiver 12b is a liquid-receiving section that separates the gas and liquid refrigerant flowing out of the condenser 12, and allows a portion of the separated liquid-phase refrigerant to flow downstream, while storing the remaining liquid-phase refrigerant as surplus refrigerant for the cycle. In this embodiment, the condenser 12 and the receiver 12b are integrally formed.

The outlet of the receiver 12b is connected to the inlet side of the branching section 13a, which branches the flow of the refrigerant flowing out of the receiver 12b. The branching section 13a is a three-way joint with three inlet and outlet ports that communicate with each other. In the branching section 13a, one of the three inlet and outlet ports is used as the inlet, and the remaining two are used as outlet ports.

One outlet of the branch 13a is connected to the inlet side of the air conditioning expansion valve 15 via the air conditioning solenoid valve 14a. The other outlet of the branch 13a is connected to the inlet side of the battery side branch 13c via the battery solenoid valve 14b.

The air conditioning solenoid valve 14a is an air conditioning opening/closing unit that opens and closes the refrigerant passage from one outlet of the branch section 13a to the inlet of the air conditioning expansion valve 15. The opening and closing operation of the air conditioning solenoid valve 14a is controlled by a control voltage output from the air conditioning control device 50. In the refrigeration cycle device 10, the air conditioning solenoid valve 14a opens and closes the refrigerant passage, thereby switching the refrigerant circuit. Therefore, the air conditioning solenoid valve 14a is a refrigerant circuit switching unit.

The air conditioning expansion valve 15 is an air conditioning pressure reducing section that reduces the pressure of the refrigerant flowing out from one outlet of the branch section 13a until it becomes a low-pressure refrigerant. Furthermore, the air conditioning expansion valve 15 is an air conditioning flow rate adjusting section that adjusts the flow rate of the refrigerant flowing into the air conditioning evaporator 16.

In this embodiment, a thermostatic expansion valve composed of a mechanical mechanism is used as the air conditioning expansion valve 15. More specifically, the air conditioning expansion valve 15 has a temperature-sensing part having a deformable member (specifically, a diaphragm) that deforms according to the temperature and pressure of the refrigerant on the outlet side of the air conditioning evaporator 16, and a valve body part that displaces according to the deformation of the deformable member to change the throttle opening.

As a result, the air conditioning expansion valve 15 changes the throttle opening so that the degree of superheat of the refrigerant on the outlet side of the air conditioning evaporator 16 approaches a predetermined reference degree of superheat (5°C in this embodiment). Here, a mechanical mechanism refers to a mechanism that operates by load due to fluid pressure or load due to an elastic member without requiring a power supply.

The outlet of the air conditioning expansion valve 15 is connected to the refrigerant inlet side of the air conditioning evaporator 16. The air conditioning evaporator 16 exchanges heat between the low-pressure refrigerant decompressed by the air conditioning expansion valve 15 and the air for air conditioning. The air conditioning evaporator 16 is an air conditioning evaporation section that evaporates the low-pressure refrigerant to cool the air for air conditioning, thereby exerting a heat absorbing effect. The air conditioning evaporator 16 is disposed in the air conditioning casing 31 of the indoor air conditioning unit 30.

The outlet of the air conditioning evaporator 16 is connected to one of the inlet sides of the junction 13b via a check valve 17. The check valve 17 allows the refrigerant to flow from the outlet side of the air conditioning evaporator 16 to one of the inlet sides of the junction 13b, and prohibits the refrigerant from flowing from one of the inlet sides of the junction 13b to the outlet side of the air conditioning evaporator 16.

The junction 13b is a three-way joint similar to the branching section 13a. In the junction 13b, two of the three inlet/outlet ports are used as inlet ports, and the remaining one is used as outlet port. The outlet port of the junction 13b is connected to the suction port side of the compressor 11.

The battery solenoid valve 14b is a cooling opening/closing part that opens and closes the refrigerant flow path from the other outlet of the branch part 13a to the inlet of the battery side branch part 13c. The basic configuration of the battery solenoid valve 14b is the same as that of the air conditioning solenoid valve 14a. In the refrigeration cycle device 10, the battery solenoid valve 14b opens and closes the refrigerant passage, thereby switching the refrigerant circuit. Therefore, the battery solenoid valve 14b, together with the air conditioning solenoid valve 14a, is a refrigerant circuit switching part. The battery solenoid valve 14b is fixed to the vehicle body.

The battery side branch 13c is a three-way joint with the same configuration as the branch 13a. The inlet side of the right battery expansion valve 18a is connected to one outlet of the battery side branch 13c. The inlet side of the left battery expansion valve 18b is connected to the other outlet of the battery side branch 13c.

The right-side battery expansion valve 18a is a cooling pressure reduction section that reduces the pressure of the refrigerant flowing out from one outlet of the battery-side branch section 13c until it becomes a low-pressure refrigerant. Furthermore, the right-side battery expansion valve 18a is a cooling flow rate adjustment section that adjusts the flow rate of refrigerant flowing into the right-side battery evaporator 19a.

In this embodiment, an electric expansion valve configured with an electrical mechanism is used as the right-side battery expansion valve 18a. More specifically, the right-side battery expansion valve 18a has a valve body portion that changes the throttle opening and an electric actuator (specifically, a stepping motor) that displaces the valve body portion.

The operation of the right-side battery expansion valve 18a is controlled by a control pulse output from the air conditioning control device 50. Furthermore, the right-side battery expansion valve 18a has a full-closing function that blocks the refrigerant passage by fully closing the throttle opening. Here, the electrical mechanism refers to a mechanism that operates when power is supplied.

The outlet of the right-side battery expansion valve 18a is connected to the refrigerant inlet side of the right-side battery evaporator 19a. The right-side battery evaporator 19a exchanges heat between the low-pressure refrigerant decompressed by the right-side battery expansion valve 18a and the cooling air blown onto the battery 70. The right-side battery evaporator 19a is a cooling evaporation section that cools the cooling air by evaporating the low-pressure refrigerant to cool the battery 70 and exerting a heat absorption effect.

The left battery expansion valve 18b is a cooling pressure reducing section that reduces the pressure of the refrigerant flowing out from the other outlet of the battery side branch section 13c until it becomes a low pressure refrigerant. Furthermore, the left battery expansion valve 18b is a cooling flow rate adjusting section that adjusts the flow rate of refrigerant flowing into the left battery evaporator 19b. The basic configuration of the left battery expansion valve 18b is the same as that of the right battery expansion valve 18a.

The outlet of the left battery expansion valve 18b is connected to the refrigerant inlet side of the left battery evaporator 19b. The left battery evaporator 19b exchanges heat between the low-pressure refrigerant decompressed by the left battery expansion valve 18b and the cooling air blown onto the battery 70. The left battery evaporator 19b is a cooling evaporation section that cools the cooling air by evaporating the low-pressure refrigerant to cool the battery 70 and exerting a heat absorption effect.

Therefore, in this embodiment, multiple cooling evaporation sections are provided. The multiple cooling evaporation sections are connected in parallel to each other with respect to the refrigerant flow. In addition, the same number of cooling flow rate adjustment sections are provided as the multiple cooling evaporation sections. Each cooling flow rate adjustment section is disposed upstream of the respective cooling evaporation section in the refrigerant flow, and is capable of individually adjusting the refrigerant flow rate flowing into each cooling evaporation section.

One inlet side of the battery side junction 13d is connected to the outlet of the right-side battery evaporator 19a. The other inlet side of the battery side junction 13d is connected to the outlet of the left-side battery evaporator 19b. The battery side junction 13d is a three-way joint with the same configuration as the junction 13b. The other inlet side of the junction 13b is connected to the outlet of the battery side junction 13d.

The above-mentioned battery solenoid valve 14b is an opening/closing part that opens and closes the cooling flow passage part 460. The cooling flow passage part 460 is a refrigerant flow passage through which the refrigerant flows from the other outlet of the branch part 13a through the battery side branch part 13c to the cooling pressure reducing part (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b). The battery solenoid valve 14b is disposed closer to the branch part 13a than the cooling pressure reducing parts 18a and 18b.

The right-side battery expansion valve 18a, the left-side battery expansion valve 18b, the right-side battery evaporator 19a, the left-side battery evaporator 19b, the battery side branch section 13c, and the battery side junction section 13d are arranged in the battery casing 41 of the battery pack 40. The battery solenoid valve 14b is arranged outside the battery casing 41.

In the battery casing 41, the refrigerant piping from the battery side branch 13c to the right battery evaporator 19a is wrapped with a heat insulating material. In the battery casing 41, the refrigerant piping from the battery side branch 13c to the left battery evaporator 19b is also wrapped with a heat insulating material. In the battery casing 41, the right battery expansion valve 18a and the left battery expansion valve 18b are also wrapped with a heat insulating material.

The insulation is made of a porous elastomer. For example, the insulation is made of ethylene propylene diene rubber (EPDM).

Here, the detailed configurations of the air conditioning evaporator 16, the right-side battery evaporator 19a, and the left-side battery evaporator 19b will be described. In the refrigeration cycle device 10, the air conditioning evaporator section (i.e., the air conditioning evaporator 16) and the cooling evaporator section (i.e., the right-side battery evaporator 19a and the left-side battery evaporator 19b) are connected in parallel with respect to the flow of the refrigerant. Furthermore, a so-called tank-and-tube type heat exchanger is used as the air conditioning evaporator 16.

A tank-and-tube heat exchanger has multiple refrigerant tubes and a pair of tanks. The refrigerant tubes are metal tubes through which the refrigerant flows. The multiple refrigerant tubes are stacked and arranged at intervals in a specific direction. An air passage is formed between adjacent refrigerant tubes to allow air to flow for heat exchange with the refrigerant.

The tank is a bottomed cylindrical metal member that extends in the stacking direction of the multiple refrigerant tubes. The pair of tanks are connected to both ends of the multiple refrigerant tubes. Inside the tank, a distribution space that distributes the refrigerant to the multiple refrigerant tubes and a collection space that collects the refrigerant flowing out from the multiple refrigerant tubes are formed.

This forms a heat exchange core that exchanges heat between the refrigerant flowing through each refrigerant tube and the air flowing through the air passage. Heat exchange fins that promote heat exchange between the refrigerant and air are arranged in the air passage. Therefore, the heat exchange area between the refrigerant and air in a tank-and-tube type heat exchanger can be defined as the sum of the front area (in other words, the projected area) of the heat exchange core when viewed from the air flow direction and the surface area of the heat exchange fins.

A so-called serpentine type heat exchanger is used as the right-side battery evaporator 19a and the left-side battery evaporator 19b.

A serpentine type heat exchanger has one or more refrigerant tubes. The refrigerant tubes are metal tubes through which the refrigerant flows. The refrigerant tubes are flat tubes with one or more holes. The refrigerant tubes are serpentine with multiple bends so that the flat surfaces face each other.

An air passage is formed between the flat surfaces of the refrigerant tubes, through which air that exchanges heat with the refrigerant flows. When there are multiple refrigerant tubes, the multiple refrigerant tubes overlap each other in the direction in which the air passage extends. In other words, the multiple refrigerant tubes are lined up in the air flow direction over the entire area from one end to the other end.

This forms a heat exchange core that exchanges heat between the refrigerant flowing through the refrigerant tubes and the air flowing through the air passage. Heat exchange fins that promote heat exchange between the refrigerant and the air are arranged in the air passage. Therefore, the heat exchange area between the refrigerant and the air in a serpentine type heat exchanger can be defined as the sum of the front area (in other words, the projected area) of the heat exchange core when viewed from the air flow direction and the surface area of the heat exchange fins.

In this embodiment, the air conditioning evaporator 16 has a heat exchange area that is greater than the sum of the heat exchange area of the right-side battery evaporator 19a and the left-side battery evaporator 19b. Furthermore, the right-side battery evaporator 19a and the left-side battery evaporator 19b have the same heat exchange area.

Next, the heat medium circuit 20 will be described. The heat medium circuit 20 is a circuit that circulates a heat medium that exchanges heat with the air for air conditioning. The heat medium circuit 20 uses an aqueous ethylene glycol solution as the heat medium. The heat medium circuit 20 has a water pump 21, a water heater 22, a heater core 23, and a reserve tank 24.

The water pump 21 pumps the heat medium toward the water heater 22. The water pump 21 is an electric impeller pump that rotates an impeller (i.e., a vane wheel) using an electric motor. The water pump 21 is disposed in the drive unit room. The rotation speed (pumping capacity) of the water pump 21 is controlled by a control voltage output from the air conditioning control device 50.

The water heater 22 is a heat medium heating unit that heats the heat medium pumped from the water pump 21. The water heater 22 is a PTC heater having a PTC element (i.e., a positive temperature coefficient thermistor). The amount of heat generated by the water heater 22 is controlled by a control voltage output from the air conditioning control device 50.

The heat medium inlet side of the heater core 23 is connected to the downstream side of the water heater 22. The heater core 23 exchanges heat between the heat medium heated by the water heater 22 and the air for air conditioning. The heater core 23 is a heat exchanger for heating that dissipates heat contained in the heat medium to the air for air conditioning, thereby heating the air for air conditioning. The heater core 23 is disposed in the air conditioning casing 31 of the indoor air conditioning unit 30.

The inlet side of the reserve tank 24 is connected to the heat medium outlet of the heater core 23. The reserve tank 24 is a storage section that stores excess heat medium in the heat medium circuit 20. In the heat medium circuit 20, the reserve tank 24 is arranged to suppress a decrease in the amount of heat medium circulating through the heat medium circuit 20. The reserve tank 24 has a supply port for replenishing the heat medium when the amount of heat medium in the heat medium circuit 20 is insufficient.

Next, we will explain the interior air conditioning unit 30. The interior air conditioning unit 30 is a unit that blows conditioned air, adjusted to an appropriate temperature for air conditioning the vehicle cabin, to appropriate locations within the vehicle cabin. The interior air conditioning unit 30 is located inside the instrument panel at the very front of the vehicle cabin.

The indoor air conditioning unit 30 houses an air conditioning blower 32, an air conditioning evaporator 16, a heater core 23, etc., in an air conditioning casing 31 that forms an air passage for the air conditioning air. The air conditioning casing 31 is molded from a resin (e.g., polypropylene) that has a certain degree of elasticity and excellent strength. An air passage is formed inside the air conditioning casing 31, through which the air conditioning air flows.

An inside/outside air switching device 33 is disposed on the most upstream side of the blown air flow of the air conditioning casing 31. The inside/outside air switching device 33 adjusts the ratio of inside air (i.e., air inside the vehicle cabin) and outside air (i.e., air outside the vehicle cabin) introduced into the air conditioning casing 31. The inside/outside air switching device 33 is an inside/outside air adjustment unit that adjusts the outside air ratio, which is the ratio of outside air in the air conditioning air flowing into the air conditioning evaporator 16 disposed inside the air conditioning casing 31.

More specifically, the inside/outside air switching device 33 is formed with an inside air inlet 33a for introducing inside air into the air conditioning casing 31, and an outside air inlet 33b for introducing outside air. Inside the inside/outside air switching device 33, an inside/outside air switching door 33c is arranged to continuously adjust the opening area of the inside air inlet 33a and the outside air inlet 33b.

The inside/outside air switching device 33 therefore adjusts the ratio of the volume of inside air to the volume of outside air introduced into the air conditioning casing 31 (i.e., the outside air rate) by displacing the inside/outside air switching door 33c. The inside/outside air switching door 33c is driven by an electric actuator 33e for the inside/outside air switching device. The operation of the electric actuator 33e for the inside/outside air switching device is controlled by a control signal output from the air conditioning control device 50.

An air conditioning blower 32 is disposed downstream of the inside/outside air switching device 33 in the blowing air flow. The air conditioning blower 32 blows the air drawn in through the inside/outside air switching device 33 toward the vehicle interior. The air conditioning blower 32 is an electric blower that drives a centrifugal multi-blade fan with an electric motor. The rotation speed (i.e., blowing capacity) of the air conditioning blower 32 is controlled by a control voltage output from the air conditioning control device 50.

The air conditioning evaporator 16 and the heater core 23 are arranged in this order in relation to the air flow downstream of the air conditioning blower 32. In other words, the air conditioning evaporator 16 is arranged upstream of the heater core 23 in the air flow.

Inside the air conditioning casing 31, there is a cold air bypass passage 35 that allows the air conditioning air after passing through the air conditioning evaporator 16 to bypass the heater core 23. Inside the air conditioning casing 31, an air mix door 34 is disposed downstream of the air flow from the air conditioning evaporator 16 and upstream of the air flow from the heater core 23.

The air mix door 34 is an air volume ratio adjustment unit that adjusts the ratio of the air volume passing through the heater core 23 side and the air volume passing through the cold air bypass passage 35, among the air for air conditioning after passing through the air conditioning evaporator 16. The air mix door 34 is driven by an electric actuator 34a for the air mix door. The operation of the electric actuator 34a for the air mix door is controlled by a control signal output from the air conditioning control device 50.

A mixing space 36 is formed downstream of the air flow of the heater core 23 and the cold air bypass passage 35 in the air conditioning casing 31. The mixing space 36 is a space where the air conditioning air heated by the heater core 23 is mixed with the air conditioning air that has passed through the cold air bypass passage 35 and has not been heated.

At the downstream side of the blown air flow of the air conditioning casing 31, an opening hole is arranged for blowing the air conditioning air that has been mixed and temperature-adjusted in the mixing space 36 into the vehicle cabin.

The openings provided are face opening 37a, foot opening 37b, and defroster opening 37c. Face opening 37a is an opening for blowing conditioned air toward the upper body of the occupant. Foot opening 37b is an opening for blowing conditioned air toward the feet of the occupant. Defroster opening 37c is an opening for blowing conditioned air toward the inner surface of the windshield.

The face opening hole 37a, the foot opening hole 37b, and the defroster opening hole 37c are connected to a face air outlet, a foot air outlet, and a defroster air outlet (none of which are shown) provided in the vehicle cabin via ducts that form air passages.

Therefore, the air mix door 34 adjusts the ratio of the air volume passing through the heater core 23 and the air volume passing through the cold air bypass passage 35, thereby adjusting the temperature of the conditioned air mixed in the mixing space 36. This adjusts the temperature of the conditioned air (i.e., the conditioned air) blown into the vehicle cabin from each air outlet.

Furthermore, face door 38a, foot door 38b, and defroster door 38c are arranged upstream of face opening hole 37a, foot opening hole 37b, and defroster opening hole 37c in the blown air flow. Face door 38a adjusts the opening area of face opening hole 37a. Foot door 38b adjusts the opening area of foot opening hole 37b. Defroster door 38c adjusts the opening area of the froster opening hole.

The face door 38a, foot door 38b, and defroster door 38c form an air outlet mode switching section that switches the air outlet mode. The face door 38a, foot door 38b, and defroster door 38c are rotated in conjunction with each other via a link mechanism or the like by an electric actuator 38d for the air outlet mode door. The operation of the electric actuator 38d for the air outlet mode door is controlled by a control signal output from the air conditioning control device 50.

Specific examples of the air outlet modes that can be switched by the air outlet mode switching unit include face mode, bi-level mode, foot mode, etc.

Face mode is an outlet mode in which the face outlet is fully opened and air is blown from the face outlet toward the upper bodies of passengers in the vehicle interior. Bi-level mode is an outlet mode in which both the face outlet and the foot outlet are open and air is blown toward the upper bodies and feet of passengers in the vehicle interior. Foot mode is an outlet mode in which the foot outlet is fully opened and the defroster outlet is only slightly opened, and air is mainly blown from the foot outlet.

In addition, the passenger can manually operate the air outlet mode off switch provided on the operation panel 60 to switch to the defroster mode. The defroster mode is an air outlet mode in which the defroster air outlet is fully open and air is blown out from the defroster air outlet onto the inside of the windshield.

Next, we will explain the battery pack 40. The battery pack 40 is a package that houses the battery 70 in a manner that allows it to be cooled.

The battery pack 40 is disposed under the floor of the vehicle compartment. The battery pack 40 is disposed below the compressor 11 and the air conditioning evaporator 16. The battery pack 40 houses a right cooling blower 42a, a left cooling blower 42b, a right battery evaporator 19a, and a left battery evaporator 19b inside a battery casing 41 that forms an air passage for cooling air. The battery casing 41 is a sealed metal case that has been electrically insulated and thermally insulated.

Inside the battery casing 41, there are formed a right cooling space 43a, a left cooling space 43b, a right air passage 44a, a left air passage 44b, and a battery space 45. The battery space 45 is a space that houses the battery 70. The right cooling space 43a is a space that houses the right cooling blower 42a, the right battery evaporator 19a, etc. The left cooling space 43b is a space that houses the left cooling blower 42b, the left battery evaporator 19b, etc.

The battery space 45 and the right cooling space 43a are in communication with each other. The battery space 45 and the left cooling space 43b are in communication with each other. The right cooling blower 42a is an electric blower that blows the cooling air sucked in from the battery space 45 toward the right battery evaporator 19a. The left cooling blower 42b is an electric blower that blows the cooling air sucked in from the battery space 45 toward the left battery evaporator 19b. The basic configuration of the right cooling blower 42a and the left cooling blower 42b is the same as that of the air conditioning blower 32. In this embodiment, the right cooling blower 42a and the left cooling blower 42b are used with a maximum blowing capacity smaller than that of the air conditioning blower 32.

The right air passage 44a is an air passage that circulates the cooling air that has passed through the right battery evaporator 19a. The right air passage 44a guides the cooling air that has passed through the right battery evaporator 19a to the right side of the battery 70 when viewed from the stacking direction of the battery 70. In other words, the right air passage 44a guides the cooling air to one end face side of the multiple battery cells.

The left air passage 44b is an air passage that circulates the cooling air that has passed through the left battery evaporator 19b. The left air passage 44b guides the cooling air that has passed through the left battery evaporator 19b to the left side of the battery 70 when viewed from the stacking direction of the battery 70. In other words, the left air passage 44b guides the cooling air to the other end face side of the multiple battery cells.

The battery casing 41 is formed with a refrigerant inlet 41a and a refrigerant outlet 41b. The refrigerant inlet 41a is an inlet-side connection portion to which the inlet-side refrigerant piping 46 is connected. The inlet-side refrigerant piping 46 forms a refrigerant flow path between the battery solenoid valve 14b and the refrigerant inlet 41a. The refrigerant that flows through the inlet-side refrigerant piping 46 flows into the battery-side branch portion 13c via the refrigerant inlet 41a.

The refrigerant outlet 41b is an outlet side connection part to which the outlet side refrigerant pipe 47 is connected. The outlet side refrigerant pipe 47 forms a refrigerant flow path between the refrigerant outlet 41b and the junction part 13b. The refrigerant that merges at the junction part 13b flows into the outlet side refrigerant pipe 47 through the refrigerant outlet 41b.

A part of the inlet side refrigerant pipe 46 is composed of an inlet side rubber hose 46a, and the remaining part of the inlet side refrigerant pipe 46 is composed of an inlet side metal pipe. The inlet side rubber hose 46a is provided to reduce the stress applied to the inlet side refrigerant pipe 46. The inlet side rubber hose 46a is an inlet side elastic member that can be elastically deformed.

For example, the inlet rubber hose 46a has an inner layer made of butyl rubber (IIR), a reinforcing layer made of resin, and an outer layer made of ethylene propylene diene rubber (EPDM). For example, the inlet metal tube is made of an aluminum alloy.

The inner diameter of the inlet rubber hose 46a is larger than the inner diameter of the inlet metal tube of the inlet refrigerant piping 46. The inlet rubber hose 46a is located in a portion of the inlet refrigerant piping 46 that is closer to the refrigerant inlet 41a than the battery solenoid valve 14b. The inlet rubber hose 46a is located below the compressor 11 and the air conditioning evaporator 16.

A part of the outlet side refrigerant piping 47 is composed of an outlet side rubber hose 47a, and the remaining part of the outlet side refrigerant piping 47 is composed of an outlet side metal tube. The outlet side rubber hose 47a is provided to reduce the stress applied to the outlet side refrigerant piping 47. The outlet side rubber hose 47a is an outlet side elastic member that can be elastically deformed.

The materials of the outlet rubber hose 47a and the outlet refrigerant pipe 47 are the same as those of the inlet rubber hose 46a and the inlet metal pipe.

The inner diameter of the outlet side rubber hose 47a is larger than the inner diameter of the outlet side metal tube of the outlet side refrigerant piping 47. The outlet side rubber hose 47a is disposed in a portion of the outlet side refrigerant piping 47 that is closer to the refrigerant outlet 41b than the junction 13b. The outlet side rubber hose 47a is located below the compressor 11 and the air conditioning evaporator 16.

The vehicle air conditioning system 1 of this embodiment also includes a steering heater 91, a seat blower 92, a seat heater 93, and a knee radiant heater 94. The steering heater 91, the seat blower 92, the seat heater 93, and the knee radiant heater 94 are heating auxiliary devices that improve the feeling of warmth for occupants when heating the vehicle interior. The operation of the heating auxiliary devices is controlled by a control signal output from the air conditioning control device 50.

More specifically, the steering heater 91 is a steering heating section that heats the steering wheel with an electric heater. The seat blower 92 is a seat blower section that blows air from inside the seat toward the occupant. The seat heater 93 is a seat heating section that heats the surface of the seat on which the occupant sits with an electric heater. The knee radiant heater 94 is a knee heating section that irradiates heat source light toward the knees of the occupant.

Next, the electrical control unit of this embodiment will be described with reference to FIG. 3. The air conditioning control device 50 is composed of a well-known microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits. The air conditioning control device 50 performs various calculations and processes based on the control program stored in the ROM, and controls the operation of various controlled devices connected to the output side.

A variety of sensors are connected to the input side of the air conditioning control device 50, including an inside air sensor 51, an outside air sensor 52, a solar radiation sensor 53, a high-pressure refrigerant pressure sensor 54, an air conditioning evaporator temperature sensor 55, a right-side cooling evaporator temperature sensor 56a, a left-side cooling evaporator temperature sensor 56b, a cooling evaporator inlet temperature sensor 56c, a cooling evaporator pressure sensor 57, a water temperature sensor 58, a battery temperature sensor 59, and a humidity sensor 59a.

The inside air sensor 51 is an inside air temperature detector that detects the inside air temperature Tr, which is the temperature inside the vehicle cabin. The outside air sensor 52 is an outside air temperature detector that detects the outside air temperature Tam. The solar radiation sensor 53 is a solar radiation amount detector that detects the amount of solar radiation Ts inside the vehicle cabin.

The high-pressure refrigerant pressure sensor 54 is a high-pressure refrigerant pressure detection unit that detects the refrigerant pressure Ph on the high-pressure side. In this embodiment, the high-pressure refrigerant pressure sensor 54 detects the pressure of the refrigerant flowing out of the receiver 12b.

The air conditioning evaporator temperature sensor 55 is an air conditioning evaporator temperature detection unit that detects the air conditioning evaporator temperature TE, which is the temperature of the air conditioning evaporator 16. In this embodiment, the air conditioning evaporator temperature sensor 55 detects the heat exchange fin temperature of the air conditioning evaporator 16. Therefore, the air conditioning evaporator temperature TE is equal to the temperature of the air conditioning air blown out from the air conditioning evaporator 16.

The right-side cooling evaporator temperature sensor 56a is a cooling evaporation section temperature detection section that detects the right-side cooling evaporator temperature TEBR, which is the temperature of the refrigerant flowing out of the right-side battery evaporator 19a. In this embodiment, the right-side cooling evaporator temperature sensor 56a detects the temperature of the refrigerant piping from the outlet of the right-side battery evaporator 19a to the battery side junction 13d.

The left cooling evaporator temperature sensor 56b is a cooling evaporation section temperature detection section that detects the left cooling evaporator temperature TEBL, which is the temperature of the refrigerant flowing out from the left battery evaporator 19b. In this embodiment, the left cooling evaporator temperature sensor 56b detects the temperature of the refrigerant piping from the outlet of the left battery evaporator 19b to the battery side junction 13d.

The cooling evaporator inlet temperature sensor 56c detects the minimum cooling evaporator temperature TEBmin, which is the temperature of the refrigerant piping from the left battery expansion valve 18b to the left battery evaporator 19b.

The cooling evaporator pressure sensor 57 is a cooling evaporator pressure detection unit that detects the cooling evaporator pressure PEB, which is the pressure of the refrigerant flowing out from the right battery evaporator 19a and the left battery evaporator 19b. The water temperature sensor 58 is a heat medium temperature detection unit that detects the heat medium temperature TW on the outlet side of the water heater 22.

The battery temperature sensor 59 is a battery temperature detection unit that detects the battery temperature TB (i.e., the temperature of the battery 70). In this embodiment, the battery temperature sensor 59 has multiple temperature sensors and detects the temperature at multiple locations on the battery 70. Therefore, the air conditioning control device 50 can also detect the temperature difference between each part of the battery 70. Furthermore, the average value of the detection values of the multiple temperature sensors is used as the battery temperature TB.

The humidity sensor 59a is a humidity detection unit that detects the relative humidity near the windshield inside the vehicle, RHW.

Furthermore, an operation panel 60 located near the instrument panel at the front of the vehicle interior is connected to the input side of the air conditioning control device 50. Operation signals from various switches provided on the operation panel 60 are input to the air conditioning control device 50.

Specific examples of the operation switches provided on the operation panel 60 include an air conditioner switch 60a, an auto switch 60b, an intake mode changeover switch 60c, an exhaust mode changeover switch 60d, an air volume setting switch 60e, an economy switch 60f, and a temperature setting switch 60g.

The air conditioner switch 60a is an air conditioning cooling request unit that requests cooling of the air conditioning air by the air conditioning evaporator 16 when operated by the occupant. The auto switch 60b is an automatic control setting unit that sets or cancels automatic air conditioning control of the vehicle air conditioner 1 when operated by the occupant.

The air inlet mode changeover switch 60c is an air inlet mode setting unit that switches the air inlet mode when operated by the occupant. The air outlet mode changeover switch 60d is an air outlet mode setting unit that switches the air outlet mode when operated by the occupant.

The air volume setting switch 60e is an air volume setting unit for manually setting the air volume of the air conditioning blower 32. The temperature setting switch 60g is a target temperature setting unit that sets the vehicle interior target temperature Tset through the operation of the occupant. The economy switch 60f is a power saving request unit that requests power saving of the refrigeration cycle device 10 through the operation of the occupant.

The air conditioning control device 50 is also electrically connected to other vehicle control devices 80. Examples of other vehicle control devices 80 include a driving force control device that controls the operation of an electric motor that outputs driving force for driving the vehicle.

The air conditioning control device 50 and the vehicle control device 80 are connected to each other so that they can communicate with each other. Therefore, based on a detection signal or an operation signal input to one of the control devices, the other control device can control the operation of various devices connected to the output side. For example, the vehicle control device 80 can change the output of the electric motor used to drive the vehicle using the battery temperature TB input to the air conditioning control device 50.

The air conditioning control device 50 is an integrated configuration of control means for controlling various controlled devices connected to its output side. In the air conditioning control device 50, the configuration (hardware and software) for controlling the operation of each controlled device constitutes a control unit that controls the operation of each controlled device.

For example, the component of the air conditioning control device 50 that controls the operation of the right battery expansion valve 18a and the left battery expansion valve 18b, which are cooling flow rate adjustment units, is the cooling flow rate control unit 50a. The cooling flow rate control unit 50a is also the throttle opening control unit. In addition, the component of the air conditioning control device 50 that controls the operation of the electric actuator 38d for the air outlet mode door that drives the air outlet mode door is the air outlet mode control unit 50b.

Next, the operation of the vehicle air conditioner 1 of this embodiment in the above configuration will be described using Figures 4 to 28. Figure 4 is a flowchart showing the control process as the main routine of the vehicle air conditioner 1 of this embodiment. This control process starts when the auto switch 60b is turned on (ON) while the vehicle system is running. Each control step described in the flowcharts in each figure is a part that realizes various functions of the air conditioning control device 50.

First, in step S1 in FIG. 4, the flags and timers configured by the memory circuit of the air conditioning control device 50 are initialized, and the above-mentioned electric actuator (specifically, the stepping motor) is initialized. Note that in the initialization in step S1, some of the flags and calculated values are read out from values stored the last time the vehicle air conditioner was stopped or the vehicle system was shut down.

For example, in this embodiment, the value of the trip counter Tcnt is read out. The trip counter Tcnt is a memory that stores the number of times the vehicle has been driven in the past, with one drive being defined as the period from starting the vehicle system to stopping it.

Next, in step S2, the operation signal from the operation panel 60 is read, and the process proceeds to step S3. In the following step S3, the vehicle environmental condition signal used for air conditioning control, i.e., the detection signal from the sensor group described above, is read. Furthermore, in step S3, the detection signal from the sensor group connected to the input side of the vehicle control device 80 and the control signal output from the vehicle control device 80 are read from the vehicle control device 80.

Next, in step S4, a target blown-out temperature TAO as a target temperature of the blown air blown into the vehicle compartment is calculated using the following formula F1.
TAO = Kset x Tset - Kr x Tr - Kam x Tam - Ks x Ts + C ... (F1)
Tset is the vehicle interior target temperature set by the temperature setting switch 60g. Tr is the inside air temperature detected by the inside air sensor 51. Tam is the outside air temperature detected by the outside air sensor 52. Ts is the amount of solar radiation detected by the solar radiation sensor 53. Furthermore, Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

Next, in step S5, the open/close state of the air conditioning solenoid valve 14a is determined. In step S5, the air conditioning solenoid valve 14a is opened when the air conditioning evaporator 16 is required to cool the air conditioning air based on the operation signal of the air conditioner switch 60a read in step S2.

Next, in step S6, the volume of air conditioning air blown by the air conditioning blower 32 and the volume of cooling air blown by the right cooling blower 42a and the left cooling blower 42b are determined.

The volume of air sent from the air conditioning blower 32 is determined based on the target blowing temperature TAO. Specifically, as shown in the control characteristics diagram of FIG. 5, in the extremely low temperature range (maximum cooling range) and extremely high temperature range (maximum heating range) of the target blowing temperature TAO, the air conditioning blower voltage applied to the air conditioning blower 32 is set to the maximum value (MAX), and the volume of air sent from the air conditioning blower 32 is set to the maximum volume.

When the target blowing temperature TAO rises from the extremely low temperature range toward the intermediate temperature range, the air conditioning blower voltage is reduced in response to the rise in the target blowing temperature TAO, thereby reducing the airflow volume of the air conditioning blower 32. When the target blowing temperature TAO falls from the extremely high temperature range toward the intermediate temperature range, the air conditioning blower voltage is reduced in response to the fall in the target blowing temperature TAO, thereby reducing the airflow volume of the air conditioning blower 32.

When the target blowing temperature TAO falls within a predetermined intermediate temperature range, the air conditioning blower voltage is set to a minimum value (min) and the airflow rate of the air conditioning blower 32 is set to a minimum.

In addition, the airflow rates of the right-side cooling fan 42a and the left-side cooling fan 42b are set to reference airflow rates, regardless of the target blowing temperature TAO or the battery temperature TB, with the cooling blower voltage applied to the right-side cooling fan 42a and the left-side cooling fan 42b being a predetermined reference voltage. The reference airflow rates of the right-side cooling fan 42a and the left-side cooling fan 42b are set to be equal to or lower than the minimum airflow rate of the air-conditioning fan 32.

Therefore, the airflow rate of the right-side cooling blower 42a and the left-side cooling blower 42b is equal to or less than the airflow rate of the air conditioning blower 32. In other words, the airflow rate of the cooling air that exchanges heat with the low-pressure refrigerant in the cooling evaporation section (in this embodiment, the total airflow rate that exchanges heat in the right-side battery evaporator 19a and the left-side battery evaporator 19b) is equal to or less than the airflow rate of the air conditioning air that exchanges heat with the low-pressure refrigerant in the air conditioning evaporation section.

Next, in step S7, the suction port mode is determined. Details of step S7 are explained using FIG. 6.

First, in step S71, it is determined whether the battery temperature TB is higher than a predetermined reference allowable temperature KTBmax (49°C in this embodiment). If it is determined in step S71 that the battery temperature TB is higher than the reference allowable temperature KTBmax, the process proceeds to step S72. If it is determined in step S71 that the battery temperature TB is not higher than the reference allowable temperature KTBmax, the process proceeds to step S76.

Here, the reference allowable temperature KTBmax is set to a temperature at which the battery 70 needs to be cooled in order to suppress deterioration of the battery 70 when the battery temperature TB is higher than the reference allowable temperature KTBmax.

In step S72, it is determined whether the outside air temperature Tam is equal to or lower than a predetermined standard anti-fogging temperature KTamd (15°C in this embodiment). If it is determined in step S72 that the outside air temperature Tam is lower than the standard anti-fogging temperature KTamd, the process proceeds to step S73. If it is determined in step S72 that the outside air temperature Tam is not equal to or lower than the standard anti-fogging temperature KTamd, the process proceeds to step S76.

Here, the standard anti-fogging temperature KTamd is set to a temperature at which fogging is likely to occur on the windshield when the outside air temperature Tam is below the standard anti-fogging temperature KTamd (15°C in this embodiment).

In step S73, it is determined whether the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO determined in step S11 described below. If it is determined in step S73 that the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, the process proceeds to step S74. If it is determined in step S73 that the air conditioning evaporator temperature TE is not higher than the target air conditioning evaporator temperature TEO, the process proceeds to step S76.

Here, when the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, the air conditioning air is not sufficiently cooled by the air conditioning evaporator 16, and the dehumidification of the air conditioning air is likely to be insufficient.

In step S74, it is determined whether or not the battery cooling operation determined in step S14 described below is permitted. If it is determined in step S74 that the battery cooling operation is permitted, the process proceeds to step S75. If it is determined in step S74 that the battery cooling operation is not permitted, the process proceeds to step S76.

The process proceeds to step S75 when it is determined that the battery 70 needs to be cooled, the windshield is prone to fogging, and the air conditioning air is not being sufficiently dehumidified, but the battery cooling operation is permitted.

Therefore, in step S75, a control signal is determined to be output to the electric actuator 33e for the inside/outside air switching device so that the outside air ratio is 100%, and the process proceeds to step S8. By setting the outside air ratio to 100%, ventilation can be performed inside the vehicle cabin, and fogging of the inner surface of the window glass can be suppressed.

In step S76, it is determined whether the outside air temperature Tam is higher than a predetermined reference high-temperature side outside air temperature KTamh (35°C in this embodiment). If it is determined in step S76 that the outside air temperature Tam is higher than the reference high-temperature side outside air temperature KTamh, the process proceeds to step S79. If it is determined in step S76 that the outside air temperature Tam is not higher than the reference high-temperature side outside air temperature KTamh, the process proceeds to step S77.

In step S77, it is determined whether the refrigerant circuit has been switched to the air conditioning battery cycle. If it is determined in step S77 that the refrigerant circuit has been switched to the air conditioning battery cycle, the process proceeds to step S79. If it is determined in step S77 that the refrigerant circuit has not been switched to the air conditioning battery cycle, the process proceeds to step S78.

In step S78, as shown in the control characteristics diagram in step S78 of FIG. 6, a control signal to be output to the electric actuator 33e for the inside/outside air switching device is determined, and the process proceeds to step S8. In step S78, a control signal to be output to the electric actuator 33e for the inside/outside air switching device is determined so as to increase the outside air ratio as the target blown air temperature TAO increases.

In step S79, a control signal is determined to be output to the electric actuator 33e for the inside/outside air switching device so that the outside air ratio is 0%, and the process proceeds to step S8. This allows relatively low-temperature inside air to be introduced into the air-conditioning evaporator 16, mitigating the rise in temperature of the air-conditioning air blown out from the air-conditioning evaporator 16.

Next, in step S8, the air outlet mode is determined. The air outlet mode is determined based on the target air outlet temperature TAO. Specifically, as the target air outlet temperature TAO rises from the low temperature range to the high temperature range, the mode is switched in the order of face mode, bi-level mode, and foot mode. Therefore, face mode is likely to be selected primarily in summer, bi-level mode primarily in spring and autumn, and foot mode primarily in winter.

In addition, when the occupant manually operates the air outlet mode change switch 60d to change the air outlet mode, the occupant's operation takes priority over the air outlet mode determined in step S8.

Next, in step S9, the power supply state of the water heater 22 is determined. Details of step S9 are described with reference to Figures 7 and 8.

In step S9, as shown in the control characteristics diagram of Figure 7, the operation of the water heater 22 is controlled based on the temperature difference ΔTW (ΔTW = TWO - TW) obtained by subtracting the heat medium temperature TW from the target heat medium temperature TWO. Specifically, when the temperature difference ΔTW is in the process of increasing, it is determined to switch the water heater 22 from de-energized to energized (ON in Figure 7) when the temperature difference ΔTW becomes equal to or greater than the reference upper limit temperature difference KΔTW1 (3°C in this embodiment).

When the temperature difference ΔTW is decreasing, if the temperature difference ΔTW becomes equal to or greater than the reference lower limit temperature difference KΔTW2 (0°C in this embodiment), it is decided to switch the water heater 22 from being energized to being de-energized (OFF in FIG. 7). The difference between the reference upper limit temperature difference KΔTW1 and the reference lower limit temperature difference KΔTW2 is the hysteresis width for preventing control hunting.

The target heat medium temperature TWO is determined by referring to a control map stored in advance in the air conditioning control device 50. In this embodiment, as shown in the control characteristic diagram of FIG. 8, the target heat medium temperature TWO is determined to increase with an increase in the target blown air temperature TAO.

Next, in step S10, the operating state of the water pump 21 is determined. Details of step S10 are described using FIG. 9.

First, in step S101, it is determined whether the heat medium temperature TW is higher than the air conditioning evaporator temperature TE. If it is determined in step S101 that the heat medium temperature TW is higher than the air conditioning evaporator temperature TE, the process proceeds to step S102. If it is determined in step S101 that the heat medium temperature TW is not higher than the air conditioning evaporator temperature TE, the process proceeds to step S104.

In step S102, it is determined whether the air conditioning blower 32 is operating. If it is determined in step S102 that the air conditioning blower 32 is operating, the process proceeds to step S103. If it is determined in step S102 that the air conditioning blower 32 is not operating, the process proceeds to step S104.

In step S103, it is decided to operate the water pump 21, and the process proceeds to step S11. In step S104, it is decided to stop the water pump 21, and the process proceeds to step S11.

Next, in step S11, the target opening degree SW of the air mix door 34 is calculated using the following formula F2: SW=(TAO-TE)/(TW-TE)×100(%) (F2)
The air conditioning evaporator temperature TE is the air conditioning evaporator temperature detected by the air conditioning evaporator temperature sensor 55. The heat medium temperature TW is the heat medium temperature detected by the water temperature sensor 58.

In formula F2, when SW=0%, the air mix door 34 is displaced to the maximum cooling position. In other words, the air mix door 34 is displaced to a position where the cold air bypass passage 35 is fully open and the air passage on the heater core 23 side is fully closed.

In addition, in formula F2, when SW=100%, the air mix door 34 is displaced to the maximum heating position. In other words, the air mix door 34 is displaced to a position where the cold air bypass passage 35 is fully closed and the air passage on the heater core 23 side is fully opened.

In this embodiment, as explained in step S9, the target heat medium temperature TWO is determined to increase with an increase in the target blowing temperature TAO. Furthermore, the target heat medium temperature TWO is determined so that the target opening degree SW becomes approximately 100% when the heat medium temperature TW increases to the target heat medium temperature TWO.

As a result, when the occupant manually operates the temperature setting switch 60g to lower the vehicle interior target temperature Tset, the temperature of the conditioned air blown into the vehicle interior can be quickly lowered by lowering the target opening degree SW.

Next, in step S12, the target air conditioning evaporator temperature TEO and the target cooling evaporator temperature TEOB are determined. Details of step S12 are described with reference to FIG. 10.

First, in step S201, a first tentative target air conditioning evaporator temperature f (TAO) is determined. Specifically, in step S201, as shown in the control characteristic diagram of step S201 in FIG. 10, it is determined that the first tentative target air conditioning evaporator temperature f (TAO) is increased in accordance with an increase in the target air outlet temperature TAO, and the process proceeds to step S202.

In step S202, a second tentative target air conditioning evaporator temperature f (outdoor air temperature) is determined. Specifically, in step S202, as shown in the control characteristics diagram in step S202 of FIG. 10, it is determined that the second tentative target air conditioning evaporator temperature f (outdoor air temperature) is increased in accordance with an increase in the outdoor air temperature Tam, and the process proceeds to step S203.

In step S203, the smaller of the first tentative target air conditioning evaporator temperature f (TAO) and the second tentative target air conditioning evaporator temperature f (outdoor air temperature) is determined as the target air conditioning evaporator temperature TEO, and the process proceeds to step S204.

In step S204, the target cooling evaporator temperature TEOB is determined. Specifically, in step S204, as shown in the control characteristic diagram of step S204 in FIG. 10, it is determined that the target cooling evaporator temperature TEOB is to be increased in accordance with an increase in the outside air temperature Tam, and the process proceeds to step S13.

Next, in step S13, the refrigerant discharge capacity of the compressor 11 (specifically, the rotation speed of the compressor 11) is determined. The compressor rotation speed is determined in step S13 not for each control period τ in which the main routine of FIG. 4 is repeated, but for each predetermined control interval (1 second in this embodiment). Details of step S13 will be described with reference to FIGS. 11 and 12.

First, in step S301, the amount of change Δf_C in the rotation speed of the compressor 11 according to the refrigerant circuit is determined, and then the process proceeds to step S302.

Specifically, in step S301, when the refrigerant circuit is switched to the battery-only cycle, a temperature deviation En is calculated by subtracting the representative temperature of the cooling evaporator section from the target cooling evaporator temperature TEOB determined in step S204. Furthermore, a deviation change rate Edot (Edot = En - (En - 1)) is calculated by subtracting the deviation En-1 calculated previously from the deviation En calculated this time.

Then, using the temperature deviation En and the deviation change rate Edot, the amount of change in the rotation speed Δf_C relative to the previous compressor rotation speed is calculated by fuzzy inference based on the membership functions and rules for the battery-only cycle previously stored in the air conditioning control device 50.

In this embodiment, the representative temperature of the cooling evaporator section is the average of the right cooling evaporator temperature TEBR and the left cooling evaporator temperature TEBL, or either one of them. For this reason, there is a possibility that an error will occur between the representative temperature and the actual temperature of the cooling evaporator section. However, since the cooling evaporator section cools the cooling air, even if a certain degree of error occurs, it will not adversely affect the cooling of the battery or the air conditioning feeling of the occupants.

When the refrigerant circuit is switched to the air conditioning only cycle or the air conditioning battery cycle, the temperature deviation En is calculated by subtracting the air conditioning evaporator temperature TE from the target air conditioning evaporator temperature TEO determined in step S203. Furthermore, the deviation change rate Edot (Edot = En - (En - 1)) is calculated by subtracting the deviation En-1 calculated previously from the deviation En calculated this time.

Then, using the temperature deviation En and the deviation change rate Edot, the amount of change in rotation speed Δf_C relative to the previous compressor rotation speed is calculated by fuzzy inference based on the membership functions and rules for the air conditioning only cycle or the air conditioning battery cycle that are stored in advance in the air conditioning control device 50.

When the refrigerant circuit is switched to the air conditioning only cycle or the air conditioning battery cycle, the air conditioning evaporator temperature TE can be fed back to determine the rotation speed change amount Δf_C. Since the air conditioning evaporator temperature TE is equal to the temperature of the air conditioning air blown out from the air conditioning evaporator 16, the air conditioning evaporator temperature TE can be appropriately adjusted without incurring overshoot, etc.

In step S302, the upper limit correction amount f (battery temperature) for the upper limit of the rotation speed of the compressor 11 is determined, and the process proceeds to step S303.

Here, when the refrigerant circuit is switched to the air conditioning only cycle, there is no need to flow refrigerant into the cooling evaporation section (i.e., the right battery evaporator 19a and the left battery evaporator 19b). Therefore, when the refrigerant circuit is switched to the air conditioning only cycle, it is desirable to determine the upper limit of the rotation speed of the compressor 11 so that the compressor 11 can achieve an efficiency equal to or higher than a predetermined value while suppressing vibration and noise.

In contrast, when the refrigerant circuit is switched to the air conditioning battery cycle, refrigerant must not only flow into the air conditioning evaporator 16, but also into the cooling evaporation section. For this reason, if the upper limit value of the rotation speed of the compressor 11 is determined in the same way as for the air conditioning only cycle, the amount of refrigerant flowing into the air conditioning evaporator 16 will decrease, and it may become impossible to cool the air for air conditioning to the desired temperature.

For this reason, when the refrigerant circuit is switched to the air conditioning battery cycle, it is necessary to determine the upper limit of the rotation speed of the compressor 11 so that both the air conditioning air and the cooling air can be cooled to appropriate temperatures. In other words, when the refrigerant circuit is switched to the air conditioning battery cycle, it is necessary to increase the upper limit of the rotation speed of the compressor 11 more than when it is switched to the air conditioning only cycle.

Therefore, in step S302, as shown in the control characteristics diagram in step S302 of FIG. 11, it is determined that the upper limit correction amount f (battery temperature) is increased as the battery temperature TB increases. Furthermore, in step S302, it is determined that the upper limit correction amount f (battery temperature) is decreased as the vehicle speed decreases. This is because the amount of heat generated by the battery 70 decreases as the vehicle speed decreases.

Furthermore, by increasing the upper limit correction amount f (battery temperature) as the battery temperature TB rises, the air conditioning evaporator temperature TE can be quickly brought closer to the target air conditioning evaporator temperature TEO. Therefore, as will be explained in step S404 below, the battery cooling operation is more likely to be permitted. As a result, the temperature rise of the battery 70 can be suppressed.

In step S303, the upper limit of the rotation speed of the compressor 11 based on the air conditioning battery requirements (hereinafter referred to as the air conditioning battery requirement upper limit) is determined according to the refrigerant circuit and vehicle speed, and the process proceeds to step S304. Therefore, step S303 is an upper limit determination unit that determines the upper limit of the refrigerant discharge capacity of the compressor 11.

Specifically, in step S303, as shown in the table of FIG. 13, when the refrigerant circuit of the refrigeration cycle device 10 is switched to the battery only cycle, it is determined that the air conditioning battery requirement upper limit value is increased as the battery temperature TB increases, regardless of the vehicle speed. This is because as the battery temperature TB increases, the amount of heat generated by the battery 70 increases, and the refrigerant flow rate required to cool the battery 70 increases.

In addition, when the refrigerant circuit is switched to the air conditioning only cycle and the vehicle speed is equal to or lower than a predetermined reference vehicle speed (in this embodiment, 25 km/h), the air conditioning battery requirement upper limit value is determined to be the first reference upper limit value (in this embodiment, 3500 rpm).

When the refrigerant circuit is switched to the air conditioning only cycle and the vehicle speed is higher than the reference vehicle speed, the air conditioning battery requirement upper limit is determined to be the second reference upper limit (5000 rpm in this embodiment).

When the refrigerant circuit is switched to the air conditioning battery cycle, the upper limit value when the refrigerant circuit is switched to the air conditioning only cycle is used as the base, and the upper limit correction amount f (battery temperature) determined in step S302 is added to the base. The value obtained by adding the upper limit correction amount f (battery temperature) to the base is then determined as the air conditioning battery requirement upper limit value.

More specifically, when the refrigerant circuit is switched to the air conditioning battery cycle and the vehicle speed is equal to or lower than the reference vehicle speed, the air conditioning battery requirement upper limit is determined to be the first reference upper limit plus the upper limit correction amount f (battery temperature). When the refrigerant circuit is switched to the air conditioning battery cycle and the vehicle speed is higher than the reference vehicle speed, the air conditioning battery requirement upper limit is determined to be the second reference upper limit plus the upper limit correction amount f (battery temperature).

Therefore, in the refrigeration cycle device 10 of this embodiment, the refrigerant charge amount can be determined based on the time when the air conditioning battery cycle is switched on.

More specifically, if the refrigerant charge amount is determined based on the time when the system is switched to the air conditioning battery cycle, there is a possibility that the refrigerant may be overcharged when the system is switched to the battery only cycle or the air conditioning only cycle. In contrast, in this embodiment, the upper limit of the rotation speed of the compressor 11 is reduced when the system is switched to the battery only cycle or the air conditioning only cycle, so that an abnormal increase in the refrigerant pressure on the high pressure side can be suppressed.

In step S304, an upper limit value of the rotation speed of the compressor 11 for suppressing noise and vibration of the compressor 11 (hereinafter referred to as the NV requirement upper limit value) is determined, and the process proceeds to step S305. Specifically, in step S304, when the vehicle speed is equal to or lower than the reference vehicle speed, the first NV upper limit value (5200 rpm in this embodiment) is determined. When the vehicle speed is higher than the reference vehicle speed, the second NV upper limit value (8600 rpm in this embodiment) is determined.

Here, as the vehicle speed decreases, road noise also decreases, making it easier for passengers to sense the noise and vibration of the compressor 11. Therefore, in this embodiment, the first NV upper limit value is set to a value lower than the second NV upper limit value.

In step S305, the smaller of the air conditioning battery requirement upper limit value and the NV requirement upper limit value determined in step S303 is determined as the upper limit value for the rotation speed of the compressor 11, and the process proceeds to step S306.

In step S306, the lower limit of the rotation speed of the compressor 11 required to execute oil recovery control (hereinafter referred to as the lower limit for oil recovery) is determined, and the process proceeds to step S307. Thus, step S306 is a lower limit determination section that determines the lower limit of the refrigerant discharge capacity of the compressor 11. In step S306, the lower limit for oil recovery is determined to be a value higher than the lower limit during normal operation when oil recovery control is not executed.

Furthermore, in step S306, as shown in the control characteristic diagram shown in step S306 of FIG. 11, it is determined that the lower limit value for oil recovery is to be increased as the outside air temperature Tam decreases.

This is because as the outside air temperature Tam drops, the flow rate of the circulating refrigerant that circulates through the cycle drops, making it easier for refrigeration oil to accumulate in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b. Therefore, as the outside air temperature Tam drops, the lower limit for oil recovery is raised to make it easier for refrigeration oil to be returned from the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b to the compressor 11.

Furthermore, in step S306, when the refrigerant circuit is switched to the air conditioning battery cycle, the lower limit for oil recovery is raised more than when the refrigerant circuit is switched to the air conditioning only cycle or the battery only cycle. This is because in the air conditioning battery cycle, the number of refrigerant paths through which the refrigerant flows is increased compared to the air conditioning only cycle and the battery only cycle, and therefore the amount of circulating refrigerant flow required to return the refrigeration oil to the compressor 11 increases.

In step S307 shown in FIG. 12, the degree of rotation speed correction of the compressor 11 when starting to cool the battery 70 (hereinafter referred to as the inflation level) is determined, and the process proceeds to step S308. The inflation level is a control flag used to determine whether the degree of rotation speed correction of the compressor 11 is "high," "medium," or "low."

In step S307, as shown in the control characteristics diagram in step S307 of FIG. 12, the raising level is determined using a judgment value (air conditioning evaporator temperature TE - target air conditioning evaporator temperature TEO) obtained by subtracting the target air conditioning evaporator temperature TEO from the air conditioning evaporator temperature TE.

When the judgment value is increasing, if the judgment value is equal to or greater than the second judgment value (-0.5°C in this embodiment), the inflation level is switched from "low" to "medium." Furthermore, if the judgment value is equal to or greater than the fourth judgment value (3°C in this embodiment), the inflation level is switched from "medium" to "high."

When the judgment value is decreasing, the inflation level is switched from "high" to "medium" when the judgment value becomes equal to or less than the third judgment value (in this embodiment, 2°C). Furthermore, when the judgment value becomes equal to or less than the first judgment value (in this embodiment, -1°C), the inflation level is switched from "medium" to "low". The difference between the first judgment value and the second judgment value, and the difference between the third judgment value and the fourth judgment value are hysteresis widths for preventing control hunting.

Therefore, in step S307, the inflation level is changed in the order of "low," "medium," and "high" as the judgment value (air conditioning evaporator temperature TE - target air conditioning evaporator temperature TEO) obtained by subtracting the target air conditioning evaporator temperature TEO from the air conditioning evaporator temperature TE increases. This is because as the air conditioning evaporator temperature TE increases, the temperature fluctuation of the air conditioning evaporator temperature TE becomes larger when cooling of the battery 70 begins.

In step S308, the amount of change in the rotation speed Δf_C determined in step S301 is changed based on the raising level determined in step S307, and the process proceeds to step S309. More specifically, the amount of change in the rotation speed Δf_C is changed in step S308 when the upper limit value of the rotation speed of the compressor 11 at this time determined in step S306 is increased by 1000 rpm or more from the upper limit value of the rotation speed of the compressor 11 at the previous time.

When the current upper limit of the rotation speed of the compressor 11 is 1000 rpm or more higher than the previous upper limit of the rotation speed of the compressor 11, and the inflation level determined in step S307 is "low," the rotation speed change amount Δf_C is not changed. Therefore, the rotation speed change amount Δf_C is maintained at the value determined in step S301.

In addition, when the current upper limit value of the rotation speed of the compressor 11 is 1000 rpm or more higher than the previous upper limit value of the rotation speed of the compressor 11, and the raising level determined in step S307 is "medium", the rotation speed change amount Δf_C is changed to 500 rpm. According to the membership function and rules of this embodiment, by changing the rotation speed change amount Δf_C to 500 rpm, it is possible to reliably increase the rotation speed change amount Δf_C.

In addition, if the current upper limit of the rotation speed of the compressor 11 is 1000 rpm or more higher than the previous upper limit of the rotation speed of the compressor 11, and the inflation level determined in step S307 is "high," the rotation speed change amount Δf_C is changed to 2000 rpm. In other cases, the rotation speed change amount Δf_C is not changed.

Therefore, in step S308, the rotation speed of the compressor 11 when starting to cool the battery 70 can be rapidly increased as the inflation level increases in the order of "low," "medium," and "high."

In step S309, the upper limit change amount f (refrigerant pressure), which is the upper limit value of the rotation speed change amount Δf_C, is determined, and the process proceeds to step S310. Specifically, in step S309, as shown in the control characteristics diagram in step S309 of FIG. 12, the upper limit change amount f (refrigerant pressure) is determined to be decreased as the high-pressure side refrigerant pressure Ph increases. This prevents the high-pressure side refrigerant pressure from increasing abnormally.

In step S310, the current rotation speed of the compressor 11 is determined, and the process proceeds to step S14. Specifically, in step S310, the smaller of the rotation speed change amount Δf_C determined in step S308 and the upper limit change amount f (refrigerant pressure) determined in step S309 is added to the previous rotation speed of the compressor 11. This determines the first temporary compressor rotation speed.

Then, the smaller of the first temporary compressor rotation speed and the upper limit of the rotation speed of the compressor 11 determined in step S305 is set as the second temporary compressor rotation speed. The larger of the second temporary compressor rotation speed and the lower limit for oil recovery determined in step S306 is set as the rotation speed of the compressor 11 this time.

Next, in step S14, the operating states of the battery solenoid valve 14b, the right battery expansion valve 18a, and the left battery expansion valve 18b are determined. The determination of the throttle openings of the right battery expansion valve 18a and the left battery expansion valve 18b in step S14 is not performed for each control period τ in which the main routine of FIG. 4 is repeated, but is performed at each predetermined control interval (2 seconds in this embodiment). Details of step S14 will be described using FIG. 14 to FIG. 25.

First, in step S401 shown in FIG. 14, it is determined whether the battery temperature TB is higher than a predetermined reference battery cooling temperature KTB1 (35° C. in this embodiment). If it is determined in step S401 that the battery temperature TB is higher than the reference battery cooling temperature KTB1, the process proceeds to step S402. If it is determined in step S401 that the battery temperature TB is not higher than the reference battery cooling temperature KTB1, the process proceeds to step S406.

The reference battery cooling temperature KTB1 is set to a temperature at which it is determined that it is desirable to cool the battery 70 when the battery temperature TB is higher than the reference battery cooling temperature KTB1. Therefore, the reference battery cooling temperature KTB1 is set to a temperature lower than the reference allowable temperature KTBmax described in step S71.

In step S406, it is decided to close the battery solenoid valve 14b. This is because when the battery temperature TB is equal to or lower than the reference battery cooling temperature KTB1, there is no need to cool the battery 70. As a result, no refrigerant is supplied to the cooling evaporation section, and the battery 70 is not cooled.

In the following step S407, the opening degree of the cooling flow rate adjustment unit (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b) is set to 5%, and the process proceeds to step S15.

This prevents both the battery solenoid valve 14b and the cooling flow rate adjustment units 18a and 18b from being closed, thereby preventing the pressure in the refrigerant piping from increasing and damaging the piping as the temperature of the refrigerant trapped between the battery solenoid valve 14b and the cooling flow rate adjustment units 18a and 18b increases. In addition, the refrigerant between the battery solenoid valve 14b and the cooling flow rate adjustment units 18a and 18b is sucked into the compressor 11 by the negative pressure caused by the operation of the compressor 11, so that the refrigeration oil in the refrigerant is returned to the compressor 11.

In step S402, it is determined whether or not the occupant has requested that the air conditioning be performed in the vehicle cabin. Specifically, in step S402, if the air conditioner switch 60a is turned on (ON) or if the air volume setting switch 60e is causing the air conditioning blower 32 to exert its blowing capacity, it is determined that the occupant has requested that the air conditioning be performed in the vehicle cabin.

If it is determined in step S402 that no passenger has requested that the vehicle be air-conditioned, the process proceeds to step S403. If no passenger has requested that the vehicle be air-conditioned, battery cooling can be performed without considering the impact on the air-conditioning in the vehicle. Therefore, in step S403, battery cooling operation is permitted, and the process proceeds to step S405.

Whether battery cooling operation is permitted or prohibited is stored in a dedicated control flag. This is the same for the other control steps.

If it is determined in step S402 that the occupant has requested that the air conditioning of the vehicle interior be performed, the process proceeds to step S404. If the occupant has requested that the air conditioning of the vehicle interior be performed, the air conditioning of the vehicle interior is being performed. Therefore, when battery cooling is performed, when the refrigerant flow rate flowing into the cooling evaporation section increases, the refrigerant flow rate flowing into the air conditioning evaporator 16 decreases, which may cause the temperature and humidity of the air for air conditioning to increase.

In other words, if battery cooling is performed at the same time as air conditioning in the vehicle cabin, the passengers may feel that the air conditioning is not as pleasant as it should be. Therefore, in step S404, as shown in the table in FIG. 16, it is determined whether or not battery cooling operation is permitted (i.e., permitted or prohibited), and the process proceeds to step S405.

In the determination of whether or not to perform the battery cooling operation in step S404 shown in FIG. 16, it is determined whether or not the defroster mode has been switched to by an occupant operating the air outlet mode changeover switch 60d. If the defroster mode has been switched to, it is determined whether or not the environmental conditions of the vehicle are such that fogging of the windshield is likely to occur, i.e., whether the anti-fogging requirement is high or low.

In this embodiment, when the outside air temperature Tam is equal to or lower than the standard anti-fogging temperature KTamd (15°C in this embodiment), it is determined that window fogging is likely to occur and the anti-fogging requirement is high. Also, when the outside air temperature Tam is higher than the standard anti-fogging temperature KTamd, it is determined that window fogging is unlikely to occur and the anti-fogging requirement is low.

If the outside air temperature Tam is equal to or lower than the standard anti-fogging temperature KTamd and it is determined that the anti-fogging requirement is high, it is determined whether the temperature of the air conditioning air has dropped low enough to prevent window fogging, i.e., whether or not anti-fogging capability is present.

Specifically, if the air conditioning evaporator temperature TE is equal to or lower than the target air conditioning evaporator temperature TEO, it is determined that the air conditioning air is sufficiently cooled in the air conditioning evaporator 16 and that the air conditioning air is sufficiently dehumidified. Therefore, if the air conditioning evaporator temperature TE is equal to or lower than the target air conditioning evaporator temperature TEO, it is determined that there is sufficient anti-fogging capability, and battery cooling operation is permitted.

In addition, if the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, it is determined that the air conditioning air is not sufficiently cooled in the air conditioning evaporator 16 and the air conditioning air is not sufficiently dehumidified. Therefore, if the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, it is determined that there is insufficient anti-fogging capability, and battery cooling operation is prohibited.

However, even if the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, if the battery temperature TB is higher than the reference allowable temperature KTBmax (49°C in this embodiment), battery cooling operation is permitted.

On the other hand, if the outside air temperature Tam is higher than the standard defogging temperature KTamd and it is determined that the defogging requirement is low, the possibility of sudden window fogging is low. Therefore, in this case, the evaporator temperature judgment value f2 (evaporator temperature) is used to determine whether or not there is defogging capability. The evaporator temperature judgment value f2 (evaporator temperature) is a control flag used to determine whether the air conditioning evaporator temperature TE is "high" or "low."

The evaporator temperature judgment value f2 (evaporator temperature) makes it easier to judge that there is anti-fogging capability compared to when the actual air conditioning evaporator temperature TE is used.

Specifically, as shown in FIG. 17, when the air conditioning evaporator temperature TE is in the process of decreasing, the evaporator temperature judgment value f2 (evaporator temperature) becomes "low" when the air conditioning evaporator temperature TE becomes equal to or lower than the target air conditioning evaporator temperature TEO plus the correction value β1. When the evaporator temperature judgment value f2 (evaporator temperature) is "low," it is determined that the air conditioning evaporator temperature TE is low and that anti-fogging capability is present. As a result, battery cooling operation is permitted.

In addition, when the air conditioning evaporator temperature TE is in the process of rising, if the air conditioning evaporator temperature TE is equal to or greater than the target air conditioning evaporator temperature TEO plus the correction value β1 and hysteresis β2, the evaporator temperature judgment value f2 (evaporator temperature) becomes "high". If the evaporator temperature judgment value f2 (evaporator temperature) is "high", it is determined that the air conditioning evaporator temperature TE is high and there is no anti-fogging capability. As a result, battery cooling operation is prohibited.

However, even if the evaporator temperature judgment value f2 (evaporator temperature) is "high", if the battery temperature TB is higher than the reference allowable temperature KTBmax (49°C in this embodiment), the battery cooling operation is permitted. In FIG. 17, hysteresis β2 is the hysteresis width for preventing control hunting.

As shown in FIG. 18, the correction value β1 is determined to be a larger value as the battery temperature TB increases. Therefore, as the battery temperature TB increases, it becomes easier to determine that there is anti-fogging capability. This is because the deterioration of the battery 70 becomes more likely to progress with the battery temperature TB, and therefore battery cooling is prioritized over ensuring comfort within the vehicle cabin.

As shown in FIG. 19, hysteresis β2 is set to a large value as the air conditioning evaporator temperature TE increases. When the air conditioning evaporator temperature TE increases, the air conditioning evaporator temperature TE is more likely to fluctuate due to fluctuations in the temperature of the air conditioning air flowing into the air conditioning evaporator 16 (so-called suction temperature). Therefore, by increasing hysteresis β2 as the air conditioning evaporator temperature TE increases, control hunting is suppressed.

Even if the vehicle is not switched to the defroster mode, the system determines whether the anti-fogging requirement is high or low, just as it does when the vehicle is switched to the defroster mode. If the outside air temperature Tam is equal to or lower than the reference anti-fogging temperature KTamd and it is determined that the anti-fogging requirement is high, the system determines whether or not the vehicle has anti-fogging capability, just as it does when the vehicle is switched to the defroster mode.

Specifically, when the air conditioning evaporator temperature TE is equal to or lower than the target air conditioning evaporator temperature TEO, it is determined that the temperature of the air conditioning air is low enough to prevent window fogging and that there is sufficient anti-fogging capability. Therefore, battery cooling operation is permitted.

In addition, when the air conditioning evaporator temperature TE is higher than the target air conditioning evaporator temperature TEO, it is determined that the temperature of the air conditioning air is not low enough to prevent window fogging, and there is insufficient anti-fogging capability. Therefore, battery cooling operation is prohibited. However, when the battery temperature TB is equal to or higher than the standard allowable temperature KTBmax, battery cooling operation is permitted.

On the other hand, if the outside air temperature Tam is higher than the reference defogging temperature KTamd and it is determined that the defogging requirement is low, the decision is made to permit or prohibit battery cooling operation based on the comfort level within the vehicle cabin. To determine the comfort level, the inside air temperature determination value f1 (battery temperature) and the evaporator temperature determination value f2 (evaporator temperature) are used. The inside air temperature determination value f1 (battery temperature) is a control flag used to determine whether the inside air temperature Tr is "high" or "low."

Specifically, as shown in FIG. 20, when the inside air temperature Tr is in the process of decreasing, if the inside air temperature Tr falls below a value obtained by adding a correction value α1 to a predetermined reference inside air temperature KTr (30°C in this embodiment), the inside air temperature judgment value f1 (battery temperature) changes from "high" to "low." If the inside air temperature judgment value f1 (battery temperature) is "low," it is judged that the inside air temperature Tr is low and the comfort level inside the vehicle cabin is high.

In addition, when the inside air temperature Tr is rising, if the inside air temperature Tr exceeds the reference inside air temperature KTr plus the correction value α1 and the hysteresis α2 (2°C in this embodiment), the inside air temperature judgment value f1 (battery temperature) changes from "low" to "high." If the inside air temperature judgment value f1 (battery temperature) is "high," it is determined that the inside air temperature Tr is high and the comfort level inside the vehicle cabin is low.

As shown in FIG. 21, the correction value α1 is determined to be a larger value as the battery temperature TB increases. Therefore, as the battery temperature TB increases, it becomes easier to determine that comfort is high. This is because the deterioration of the battery 70 becomes more likely to progress with the battery temperature TB, and therefore battery cooling is given priority over ensuring comfort within the vehicle cabin.

Furthermore, the comfort level inside the vehicle cabin is judged using the evaporator temperature judgment value f2 (evaporator temperature). This judgment is essentially the same as the judgment of the presence or absence of anti-fogging capability that is made when the vehicle is switched to the defroster mode.

Specifically, when the evaporator temperature judgment value f2 (evaporator temperature) is "low," it is determined that the air conditioning evaporator temperature TE is low and the comfort level in the vehicle cabin is high. On the other hand, when the evaporator temperature judgment value f2 (evaporator temperature) is "high," it is determined that the air conditioning evaporator temperature TE is high and the comfort level in the vehicle cabin is low.

If the comfort level is judged to be high both in the comfort level judgement using the inside air temperature judgement value f1 (battery temperature) and in the comfort level judgement using the evaporator temperature judgement value f2 (evaporator temperature), battery cooling operation is permitted.

In addition, if the comfort level is determined to be low in at least one of the comfort level determinations using the inside air temperature determination value f1 (battery temperature) and the comfort level determination using the evaporator temperature determination value f2 (evaporator temperature), a decision is made to permit or prohibit battery cooling operation based on the elapsed time determination value f3 (battery temperature).

Specifically, as shown in FIG. 22, if the elapsed time since the start of the vehicle system is equal to or greater than the reference elapsed time TIMER, the elapsed time judgment value f3 (battery temperature) is permitted, and the battery cooling operation is permitted. Also, if the elapsed time since the start of the vehicle system does not exceed the reference elapsed time TIMER, the elapsed time judgment value f3 (battery temperature) is prohibited, and the battery cooling operation is prohibited.

This ensures that battery cooling operation is permitted based on the amount of time that has elapsed since the vehicle system was started, even if battery cooling operation is not permitted for a long period of time, such as when an occupant has the window open.

Furthermore, as shown in FIG. 23, the reference elapsed time TIMER is set to a shorter time as the battery temperature TB increases. Therefore, as the battery temperature TB increases, battery cooling can be permitted in a short time, and deterioration of the battery 70 can be effectively suppressed.

In step S405 of FIG. 14, it is determined whether or not battery cooling operation is permitted. If it is determined in step S405 that battery cooling operation is not permitted (i.e., battery cooling operation is prohibited), the process proceeds to step S406. If it is determined in step S405 that battery cooling operation is permitted, the process proceeds to step S408. In step S408, it is determined to open the battery solenoid valve 14b, and the process proceeds to step S409.

Here, we consider the case where the air conditioning only cycle is switched to the air conditioning battery cycle by deciding to open the battery solenoid valve 14b in step S408.

In this case, the refrigeration cycle device 10 may experience a sudden increase in the refrigerant flow rate flowing into the cooling evaporation section, and a sudden decrease in the refrigerant flow rate flowing into the air conditioning evaporator 16 connected in parallel to the cooling evaporation section. As a result, the air conditioning air may not be sufficiently cooled in the air conditioning evaporator 16.

Therefore, in this embodiment, the following control steps are performed to gradually increase the flow rate of the refrigerant flowing into the cooling evaporation section over time.

First, in step S409, it is determined whether opening the battery solenoid valve 14b in step S408 will cause the battery solenoid valve 14b to change from a closed state to an open state. If it is determined in step S409 that the battery solenoid valve 14b will change from a closed state to an open state, the process proceeds to step S410.

In step S410, it is determined whether the refrigerant circuit has been switched from the air conditioning only cycle to the air conditioning battery cycle as a result of the decision to open the battery solenoid valve 14b in step S408. If it is determined in step S410 that the refrigerant circuit has been switched from the air conditioning only cycle to the air conditioning battery cycle, the process proceeds to step S411.

In step S411, the time for executing the gradual change control (hereinafter referred to as the time limit LTop) is determined, and the process proceeds to step S412. In step S411, as shown in the control characteristics diagram of FIG. 24, the time limit LTop during normal operation when oil recovery control is not being executed and the time limit LTop during oil recovery control are determined. Therefore, step S411 is a time limit determination unit. In addition, the time during oil recovery control refers to the time when oil recovery control is being executed.

The time limit LTop during normal operation is determined so that it becomes longer as the outside air temperature Tam rises. This is because as the outside air temperature Tam rises, the amount of heat dissipated by the high-pressure refrigerant in the condenser 12 decreases, and the time required to lower the temperature of the cooling evaporation section becomes longer. Also, as the outside air temperature Tam falls, there is a higher possibility that the temperature of the cooling evaporation section will drop unnecessarily.

The time limit LTop during oil recovery control is determined so that it becomes shorter as the outside air temperature Tam rises. This is because as the outside air temperature Tam rises, refrigeration oil becomes less likely to remain in the air conditioning evaporator 16, the right battery evaporator 19a, the left battery evaporator 19b, etc.

In step S412, the maximum throttle opening (hereinafter referred to as the limited opening LDop) of the cooling flow rate adjustment unit (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b) during gradual change control is determined, and the process proceeds to step S413. In step S412, as shown in the control characteristics diagram of FIG. 25, the limited opening LDop during normal operation and the limited opening LDop during oil recovery control are determined. Therefore, step S412 is a limited opening determination unit.

The limit opening LDop is defined as the opening ratio relative to when the cooling flow rate adjustment unit is fully open (i.e., 100%).

The limit opening LDop during normal operation is determined so that it increases as the outside air temperature Tam increases. This is because as the outside air temperature Tam increases, the amount of heat released by the high-pressure refrigerant in the condenser 12 decreases, and the time required to lower the temperature of the cooling evaporation section increases. Also, as the outside air temperature Tam decreases, there is a high possibility that the temperature of the cooling evaporation section will be unnecessarily lowered.

The limit opening LDop during oil recovery control is determined so that it decreases as the outside air temperature Tam increases. This is because as the outside air temperature Tam increases, refrigeration oil is less likely to accumulate in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b. Furthermore, the limit opening LDop during oil recovery control is determined within a range in which at least the refrigeration oil remaining in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b can be returned to the compressor 11.

In step S413, the throttle opening ODop of the cooling flow rate adjustment unit during gradual change control is determined, and the process proceeds to step S415. In step S413, the throttle opening ODop is changed according to the switching elapsed time Top after it is determined that the battery solenoid valve 14b has changed from a closed state to an open state.

Specifically, in step S413, the throttle opening ODop of the cooling flow rate adjustment unit is increased within a range equal to or less than the limit opening LDop. Furthermore, in step S413, the throttle opening ODop of the cooling flow rate adjustment unit is increased so that the increase in the throttle opening ODop per unit time is a predetermined reference increase (in this embodiment, the increase per second is 0.1% of the maximum opening).

If the aperture opening ODop reaches the limit opening LDop before the switching elapsed time Top reaches the limit time LTop, the aperture opening ODop is maintained at the limit opening LDop until the switching elapsed time Top reaches the limit time LTop. Also, if the switching elapsed time Top reaches the limit time LTop, the gradual change control ends regardless of the aperture opening ODop. In other words, the limit opening LDop is set to 100%.

On the other hand, if it is determined in step S409 that the battery solenoid valve 14b has not changed from a closed state to an open state, the process proceeds to step S414. Also, if it is determined in step S410 that the refrigerant circuit has not been switched from the air conditioning only cycle to the air conditioning battery cycle, the process proceeds to step S414. If the process proceeds to step S414, there is no need to execute gradual change control, so the limit opening LDop is set to 100%.

In step S415 shown in FIG. 15, it is determined whether oil recovery control is being executed. If it is determined in step S415 that oil recovery control is being executed, the process proceeds to steps S416 to S417. If it is determined in step S415 that oil recovery control is not being executed, the process proceeds to steps S418 to S419.

In steps S416 and S418, the value of the frost determination flag is determined, and the process proceeds to step S420. If it is determined that frost has formed on the cooling evaporation section, the frost determination flag stores "Yes." If it is determined that frost has not formed on the cooling evaporation section, the flag stores "No."

In step S416, when the minimum temperature TEBmin of the cooling evaporator temperature is in the process of decreasing, the frost determination flag is changed from "absent" to "present" when the minimum temperature TEBmin is equal to or lower than a predetermined first reference frost temperature KTEB1 (-5°C in this embodiment). Also, when the minimum temperature TEBmin of the cooling evaporator temperature is in the process of increasing, the frost determination flag is changed from "present" to "absent" when the minimum temperature TEBmin is equal to or higher than a predetermined second reference frost temperature KTEB2 (-3°C in this embodiment).

The difference between the first reference frost temperature KTEB1 and the second reference frost temperature KTEB2 is the hysteresis width to prevent control hunting.

In step S417, the right oil return opening DRoil and the left oil return opening DLoil are set to the limit opening LDop determined in step S412.

In step S418, when the minimum temperature TEBmin is in the process of decreasing, the frost determination flag is changed from "absent" to "present" when the minimum temperature TEBmin becomes equal to or lower than the predetermined third reference frost temperature KTEB3 (-1°C in this embodiment). Also, when the minimum temperature TEBmin of the cooling evaporator temperature is in the process of increasing, the frost determination flag is changed from "present" to "absent" when the minimum temperature TEBmin becomes equal to or higher than the predetermined fourth reference frost temperature KTEB4 (0°C in this embodiment).

The difference between the third reference frost temperature KTEB3 and the fourth reference frost temperature KTEB4 is the hysteresis width to prevent control hunting.

In step S419, the right oil return opening DRoil and the left oil return opening DLoil are set to 0%.

In this embodiment, in steps S416 and S418, the temperature detected by the cooling evaporator inlet temperature sensor 56c is set as the minimum cooling evaporator temperature TEBmin.

Furthermore, the first reference frost temperature KTEB1 is set to a temperature lower than the third reference frost temperature KTEB3. The second reference frost temperature KTEB2 is set to a temperature lower than the fourth reference frost temperature KTEB4. Therefore, while oil recovery control is being performed, the frost determination flag is less likely to become "Yes" than during normal operation.

In step S420, the frost determination flag is used to determine whether frost has formed in the cooling evaporation section. If the frost determination flag is set to "Yes" in step S420, the process proceeds to step S421. In step S421, the cooling flow rate adjustment section (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b) is fully closed (0%). This prevents refrigerant from flowing into the cooling evaporation section, and the cooling evaporation section is defrosted.

If the frost determination flag is set to "None" in step S420, proceed to step S422. In step S422, it is determined whether the refrigerant circuit is an air conditioning battery cycle.

If it is determined in step S422 that the refrigerant circuit is an air conditioning battery cycle, the process proceeds to step S423. In step S423, the minimum oil circulation opening Dmin is set to 1% and the process proceeds to step S425.

If it is determined in step S422 that the refrigerant circuit is not an air conditioning battery cycle (i.e., the refrigerant circuit is a battery only cycle), the process proceeds to step S424. In step S424, the minimum oil circulation opening Dmin is set to 2%, and the process proceeds to step S425.

As a result, when the refrigerant circuit is a battery-only cycle, the minimum oil circulation opening Dmin is greater than when the refrigerant circuit is an air conditioning battery cycle.

That is, in the case of a battery-only cycle, the refrigeration oil also returns to the compressor 11 via the air conditioning evaporator 16, so even if the minimum opening of the right-side battery expansion valve 18a and the left-side battery expansion valve 18b is small, the refrigeration oil can be sufficiently returned to the compressor 11. On the other hand, in the case of a battery-only cycle, the refrigeration oil does not return to the compressor 11 via the air conditioning evaporator 16, but only via the right-side battery evaporator 19a and the left-side battery evaporator 19b. Therefore, by increasing the minimum opening of the right-side battery expansion valve 18a and the left-side battery expansion valve 18b, the amount of refrigeration oil circulating is ensured, and the refrigeration oil can be sufficiently returned to the compressor 11.

In step S425, the right throttle opening ODR of the right battery expansion valve 18a is determined, and the process proceeds to step S426. The right throttle opening ODR is determined so that the right superheat SHBR of the refrigerant on the outlet side of the right battery evaporator 19a approaches a predetermined target cooling side superheat SHBO (10°C in this embodiment).

Specifically, in step S425, the right-side change amount fR (right-side superheat) of the right-side throttle opening ODR is determined. In this embodiment, as shown in the control characteristic diagram in step S425 of FIG. 15, the right-side change amount fR (right-side superheat) is determined to increase with an increase in the value obtained by subtracting the target cooling side superheat SHBO (10°C in this embodiment) from the right-side superheat SHBR.

Furthermore, in step S425, the right-side throttle opening ODR is set to the maximum value among the previous right-side throttle opening ODR plus the right-side change amount fR (right-side superheat degree), the smaller value of the throttle opening ODop during gradual change control during normal operation determined in step S413, the right-side oil return opening DRoil, and the minimum oil circulation opening Dmin.

In step S426, the left throttle opening ODL of the left battery expansion valve 18b is determined, and the process proceeds to step S15. The left throttle opening ODL is basically determined to a value equivalent to the right throttle opening ODR. In other words, the left throttle opening ODL is determined to be an increase or decrease amount equivalent to the right throttle opening ODR in synchronization with the determination of the right throttle opening ODR.

However, when the left superheat degree SHBL and the right superheat degree SHBR of the refrigerant on the outlet side of the left battery evaporator 19b diverge, the throttle opening of the left battery expansion valve 18b is corrected. Specifically, in step S426, as shown in the control characteristic diagram in step S426 of FIG. 15, it is determined that the left correction amount is increased as the value obtained by subtracting the right superheat degree SHBR from the left superheat degree SHBL increases.

Furthermore, in step S426, the left throttle opening ODL is determined as the smaller of the previous right throttle opening ODR plus the right change amount fR (right superheat) and the left correction amount, the throttle opening ODop during gradual change control during normal operation determined in step S413, the left oil return opening DLoil, and the minimum oil circulation opening Dmin. The right superheat SHBR and the left superheat SHBL are derived from the right cooling evaporator temperature TEBR, the left cooling evaporator temperature TEBL, and the cooling evaporator pressure PEB.

Next, in step S15, the operating rate of the outdoor air fan 12a (i.e., the amount of outdoor air blown) is determined. The amount of air blown by the outdoor air fan 12a is determined based on the high-pressure side refrigerant pressure Ph. Specifically, as shown in the control characteristics diagram of FIG. 26, as the refrigerant pressure Ph increases, the operating rate of the outdoor air fan 12a is increased to increase the amount of air blown.

Next, in step S16, the air conditioning control device 50 outputs control signals and control voltages to the various controlled devices so that the control state determined in steps S5 to S15 described above is obtained. Next, in step S17, the system waits for a control period τ (250 ms in this embodiment), and returns to step S2 when it determines that the control period τ has elapsed.

In a refrigeration cycle device in which refrigeration oil is mixed into the refrigerant, as in this embodiment, the refrigeration oil may accumulate in the refrigerant circuit. In particular, refrigeration oil is likely to accumulate in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b, which evaporate the liquid phase refrigerant. Such accumulation of refrigeration oil reduces the heat exchange performance of the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b.

Therefore, in the vehicle air conditioner 1 of this embodiment, oil recovery control can be executed to return refrigeration oil remaining in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b of the refrigeration cycle device 10 to the compressor 11. The oil recovery control will be explained using FIG. 27. The control process for the oil recovery control shown in FIG. 27 is executed in parallel with the control process of the main routine shown in FIG. 4.

First, in step S801, it is determined whether or not it is the start of air conditioning operation in which the air conditioning air is cooled by the air conditioning evaporator 16. Specifically, in step S801, it is determined that the start of air conditioning operation is the time when the air conditioner switch 60a is turned on (ON) from a non-on (OFF) state.

Therefore, the start of air conditioning operation is when the air conditioning solenoid valve 14a goes from a closed state to an open state. If the air conditioner switch 60a is already turned on when the vehicle system is started, the start of the vehicle system is the start of air conditioning operation.

If it is determined in step S801 that it is time to start air conditioning operation, proceed to step S802. If it is determined in step S801 that it is not time to start air conditioning operation, proceed to step S806.

If the air conditioning operation has not yet started, the air conditioning in the vehicle cabin may already be in progress, and executing oil recovery control may affect the air conditioning in the vehicle cabin. Therefore, in step S806, it is decided not to execute oil recovery control, and the control process for oil recovery control is terminated.

In step S802, it is determined whether the trip counter Tcnt is equal to or greater than a predetermined reference number KTcnt (five times in this embodiment). If it is determined in step S802 that the trip counter Tcnt is equal to or greater than the reference number KTcnt, the process proceeds to step S803. If it is determined in step S802 that the trip counter Tcnt is not equal to or greater than the reference number KTcnt, the process proceeds to step S806.

In step S803, it is determined whether or not battery cooling operation is permitted. If it is determined in step S803 that battery cooling operation is not permitted, the process proceeds to step S804. If it is determined in step S803 that battery cooling operation is permitted, the process proceeds to step S806.

Here, when air conditioning operation has started and battery cooling operation is permitted, refrigerant is supplied not only to the air conditioning evaporator 16, but also to the right-side battery evaporator 19a and the left-side battery evaporator 19b. Therefore, even if oil recovery control is not performed, the refrigeration oil remaining in the air conditioning evaporator 16, the right-side battery evaporator 19a, and the left-side battery evaporator 19b can be returned to the compressor 11.

In step S804, similar to step S420, the frost determination flag is used to determine whether frost has formed on the cooling evaporator. If the frost determination flag is determined to be "absent" in step S804, the process proceeds to step S805. If the frost determination flag is determined to be "present" in step S804, the process proceeds to step S806.

In step S805, oil recovery control is executed, and the process proceeds to step S807. Specifically, in the oil recovery control, the battery solenoid valve 14b is opened, and the compressor 11 is operated at the rotation speed determined in step S13. In other words, in the oil recovery control, the refrigerant circuit is switched to the air conditioning battery cycle, and the refrigerant is circulated through the air conditioning evaporator section and the cooling evaporator section.

In addition, whether or not oil recovery control is being executed is stored in a dedicated control flag. Therefore, if the dedicated control flag does not store that oil recovery control is being executed, normal operation will occur with oil recovery control not being executed.

In step S807, it is determined whether the oil recovery control has been completed. Specifically, in step S807, it is determined whether the execution time of the oil recovery control has reached the time limit LTop for the oil recovery control determined in step S411. Then, when the execution time of the oil recovery control has reached the time limit LTop, it is determined that the oil recovery control has been completed.

If it is determined in step S807 that the oil recovery control has been completed, the process proceeds to step S808. In step S808, the trip counter Tcnt is reset (i.e., the trip counter Tcnt is set to 0), and the process returns to step S801. If it is determined in step S807 that the oil recovery control has not been completed, the process returns to step S801 again, with the value of the trip counter Tcnt maintained.

As is clear from the control of steps S801 to S804 described above, the oil recovery control is executed when air conditioning operation starts. In other words, the oil recovery control is executed when the air conditioning evaporator 16 is requested to cool the air conditioning air by the operation of the occupant. In other words, the oil recovery control is executed when the air conditioning evaporator 16 starts cooling the air conditioning air.

For this reason, in the vehicle air conditioner 1 of this embodiment, the refrigerant circuit of the refrigeration cycle device 10 is switched as shown in the diagram of Figure 28.

Specifically, if the air conditioner switch 60a is not turned on and the battery cooling operation is permitted in step S14, the system is basically switched to the battery only cycle. Note that if the air conditioner switch 60a is not turned on and the battery cooling operation is prohibited, the compressor 11 is stopped, so the system may be switched to any refrigerant circuit.

In addition, when the air conditioner switch 60a is turned on and battery cooling operation is permitted, the cycle is switched to air conditioning/battery cycle. When the air conditioner switch 60a is turned on and battery cooling operation is prohibited, the cycle is basically switched to air conditioning only cycle. However, even when the air conditioner switch 60a is turned on and battery cooling operation is prohibited, the cycle is switched to air conditioning/battery cycle while oil recovery control is being executed.

When the refrigeration cycle device 10 is switched to the air conditioning only cycle, the air conditioning mode is operated in such a way that refrigerant is allowed to flow into the air conditioning evaporator section and refrigerant is prohibited from flowing into the cooling evaporator section.

In the refrigeration cycle device 10 in air conditioning mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The high-pressure refrigerant that flows into the condenser 12 exchanges heat with the outside air blown by the outside air fan 12a and condenses. The refrigerant condensed in the condenser 12 is separated into gas and liquid in the receiver 12b.

Since the battery solenoid valve 14b is closed, the liquid-phase refrigerant that flows out of the receiver 12b flows through the branch 13a and the air conditioning solenoid valve 14a into the air conditioning expansion valve 15 and is reduced in pressure. The low-pressure refrigerant reduced in pressure by the air conditioning expansion valve 15 flows into the air conditioning evaporator 16.

The refrigerant that flows into the air conditioning evaporator 16 exchanges heat with the air for air conditioning blown from the air conditioning blower 32 and evaporates. This cools the air for air conditioning. The refrigerant that flows out of the air conditioning evaporator 16 is sucked into the compressor 11 via the check valve 17 and the junction 13b, and is compressed again.

In the heat medium circuit 20 in air conditioning mode, the heat medium pumped from the water pump 21 is heated by the water heater 22. The heat medium heated by the water heater 22 flows into the heater core 23. The heat medium that flows into the heater core 23 exchanges heat with the air for air conditioning that has been cooled by the air conditioning evaporator 16. This reheats the air for air conditioning.

The heat medium flowing out of the heater core 23 is sucked into the water pump 21 via the reserve tank 24 and pumped out again.

In the indoor air conditioning unit 30 in air conditioning mode, air flowing in from the inside/outside air switching device 33 is drawn into the air conditioning blower 32. The air for air conditioning blown from the air conditioning blower 32 flows into the air conditioning evaporator 16 and is cooled. A portion of the air for air conditioning cooled in the air conditioning evaporator 16 is reheated in the heater core 23 depending on the opening degree of the air mix door 34.

The conditioned air heated by the heater core 23 and the conditioned air that has passed through the cold air bypass passage 35 are mixed in the mixing space 36 and approach the target outlet temperature TAO. The conditioned air adjusted to an appropriate temperature in the mixing space 36 is then blown out to an appropriate location in the vehicle cabin according to the air outlet mode. This provides comfortable air conditioning in the vehicle cabin.

In addition, when the refrigeration cycle device 10 is switched to the battery-only cycle, the cooling mode operation is executed, which prohibits the flow of refrigerant into the air conditioning evaporator and allows the refrigerant to flow into the cooling evaporator.

In the refrigeration cycle device 10 in cooling mode, the refrigerant condensed in the condenser 12 is separated into gas and liquid in the receiver 12b, as in the air conditioning only cycle. The liquid phase refrigerant flowing out of the receiver 12b flows into the battery side branch 13c via the branch 13a and the battery solenoid valve 14b because the air conditioning solenoid valve 14a is closed.

The refrigerant flowing out from one of the outlets of the battery-side branch 13c flows into the right-side battery expansion valve 18a and is reduced in pressure. The low-pressure refrigerant reduced in pressure by the right-side battery expansion valve 18a flows into the right-side battery evaporator 19a.

The refrigerant that flows into the right-side battery evaporator 19a evaporates through heat exchange with the cooling air blown from the right-side cooling blower 42a. This cools the cooling air. The refrigerant that flows out of the right-side battery evaporator 19a is sucked into the compressor 11 via the battery-side junction 13d and junction 13b, and is compressed again.

The refrigerant flowing out from the other outlet of the battery-side branch 13c flows into the left battery expansion valve 18b and is reduced in pressure. The low-pressure refrigerant reduced in pressure by the left battery expansion valve 18b flows into the left battery evaporator 19b.

The refrigerant that flows into the left battery evaporator 19b evaporates through heat exchange with the cooling air blown from the left cooling blower 42b. This cools the cooling air. The refrigerant that flows out of the left battery evaporator 19b is sucked into the compressor 11 via the battery side junction 13d and junction 13b, and is compressed again.

In the battery pack 40 in cooling mode, air in the battery space 45 is drawn into the right-side cooling blower 42a and the left-side cooling blower 42b. The cooling air blown from the right-side cooling blower 42a and the left-side cooling blower 42b flows into the right-side battery evaporator 19a and the left-side battery evaporator 19b and is cooled.

The cooling air cooled by the right-side battery evaporator 19a is guided to the battery space 45 via the right-side air passage 44a and is blown onto the right side of the battery 70. This cools one end face of the multiple battery cells. The cooling air cooled by the left-side battery evaporator 19b is guided to the battery space 45 via the left-side air passage 44b and is blown onto the left side of the battery 70. This cools the other end face of the multiple battery cells.

In addition, when the refrigeration cycle device 10 is switched to the air conditioning battery cycle, the air conditioning cooling mode is operated in which refrigerant flows into the air conditioning evaporator and into the cooling evaporator.

In the refrigeration cycle device 10 in the air conditioning cooling mode, the refrigerant condensed in the condenser 12 is separated into gas and liquid in the receiver 12b, as in the air conditioning only cycle and the battery only cycle. The liquid phase refrigerant flowing out of the receiver 12b flows into the branch section 13a.

The refrigerant flowing out from one outlet of the branch 13a flows into the air conditioning expansion valve 15 via the air conditioning solenoid valve 14a, just as when the system is switched to the air conditioning only cycle. Then, the air for air conditioning is cooled in the air conditioning evaporator 16, just as when the system is switched to the air conditioning only cycle.

The refrigerant flowing out from the other outlet of the branch 13a flows into the battery side branch 13c via the battery solenoid valve 14b, just as when the system is switched to the battery-only cycle. Then, just as when the system is switched to the battery-only cycle, the cooling air is cooled in the right battery evaporator 19a and the left battery evaporator 19b.

In the air conditioning cooling mode, the heat medium circuit 20 and the interior air conditioning unit 30 operate in the same way as when switched to the air conditioning only cycle. Therefore, even when the refrigerant circuit of the refrigeration cycle device 10 is switched to the air conditioning battery cycle, air for air conditioning that has been appropriately adjusted in temperature is blown out to appropriate locations in the vehicle cabin, achieving comfortable air conditioning in the vehicle cabin.

In the battery pack 40 in the air conditioning cooling mode, each component operates in the same way as when it is switched to the battery only cycle. Therefore, the battery 70 can be cooled even when the refrigerant circuit of the refrigeration cycle device 10 is switched to the air conditioning battery cycle.

Furthermore, when the refrigerant circuit of the refrigeration cycle device 10 is switched to the air conditioning battery cycle, the refrigerant can be circulated through the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b. Therefore, by circulating the refrigerant at a flow rate required to execute the oil recovery control, the refrigerant remaining in the air conditioning evaporator 16, the right battery evaporator 19a, and the left battery evaporator 19b can be returned to the compressor 11.

In addition, in the vehicle air conditioner 1 of this embodiment, as described in steps S406 and S407, when there is no request to cool the battery 70, the air conditioning control device 50 closes the battery solenoid valve 14b and opens the cooling pressure reduction section (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b) to an opening degree that allows the refrigerant to pass through (5% in this embodiment).

This prevents both the battery solenoid valve 14b and the cooling pressure reduction sections 18a, 18b from being closed. This prevents the pressure in the cooling flow passage section 460 from increasing due to an increase in the temperature of the refrigerant trapped between the battery solenoid valve 14b and the cooling pressure reduction sections 18a, 18b. This prevents the refrigerant piping from being damaged by an increase in pressure in the cooling flow passage section 460.

Furthermore, the refrigerant between the battery solenoid valve 14b and the cooling pressure reducing sections 18a, 18b is sucked into the compressor 11 by the negative pressure caused by the operation of the compressor 11, so that the refrigeration oil in the refrigerant can be returned to the compressor 11. As a result, the compressor 11 can be cooled and the seizure of the compressor 11 can be suppressed.

In addition, in the vehicle air conditioner 1 of this embodiment, the battery solenoid valve 14b is arranged closer to the branching section 13a than the cooling pressure reducing sections 18a and 18b. This makes the refrigerant flow path between the battery solenoid valve 14b and the cooling pressure reducing sections 18a and 18b longer than when the battery solenoid valve 14b is arranged closer to the cooling pressure reducing sections 18a and 18b than the branching section 13a. This makes it possible to increase the amount of refrigerant and the amount of refrigerant oil when the refrigerant between the battery solenoid valve 14b and the cooling pressure reducing sections 18a and 18b is sucked into the compressor 11 by the negative pressure caused by the operation of the compressor 11. As a result, the compressor 11 can be more reliably cooled and the compressor 11 can be more reliably prevented from burning out.

In addition, in the vehicle air conditioner 1 of this embodiment, the cooling pressure reduction section (i.e., the right battery expansion valve 18a and the left battery expansion valve 18b) is disposed within the battery casing 41 of the battery pack 40. This makes it possible to prevent the cold heat of the refrigerant downstream of the cooling pressure reduction sections 18a and 18b from being released to the outside of the battery casing 41. This improves the cooling efficiency of the battery 70.

In addition, in the vehicle air conditioner 1 of this embodiment, a portion of the inlet side refrigerant pipe 46 is an elastically deformable inlet side rubber hose 46a, and at least a portion of the outlet side refrigerant pipe 47 is an elastically deformable outlet side rubber hose 47a. As a result, the inlet side rubber hose 46a and the outlet side rubber hose 47a can absorb stress and vibration by elastically deforming, thereby suppressing damage to the cooling refrigerant pipe.

In addition, in the vehicle air conditioner 1 of this embodiment, the inlet rubber hose 46a is arranged at a portion of the inlet refrigerant pipe 46 closer to the refrigerant inlet 41a than the branching portion 13a, and the outlet rubber hose 47a is arranged at a portion of the outlet refrigerant pipe 47 closer to the refrigerant outlet 41b than the merging portion 13b. This reduces the stress applied to the inlet refrigerant pipe 46 and the outlet refrigerant pipe 47 by the connection between the inlet refrigerant pipe 46 and the outlet refrigerant pipe 47 and the casing 41.

In this embodiment, the inner diameter of the inlet rubber hose 46a is larger than the inner diameter of the inlet refrigerant pipe 46, and the inner diameter of the outlet rubber hose 47a is larger than the inner diameter of the outlet refrigerant pipe 47. Therefore, refrigeration oil is likely to remain in the inlet rubber hose 46a and the outlet rubber hose 47a.

In this embodiment, the inlet rubber hose 46a and the outlet rubber hose 47a are located below the compressor 11 in the vehicle.

In consideration of these points, in the vehicle air conditioner 1 of this embodiment, as described in the control process for oil recovery control, oil recovery control is executed when the air conditioning evaporator 16 starts cooling the air for air conditioning.

In addition, in the vehicle air conditioner 1 of this embodiment, the right-side battery expansion valve 18a and the right-side battery evaporator 19a, and the left-side battery expansion valve 18b and the left-side battery evaporator 19b are arranged in parallel with each other in the refrigerant flow. This makes it possible to ensure a large heat exchange area while suppressing the accumulation of refrigeration oil.

In this embodiment, there are multiple battery evaporators. Specifically, there are a right-side battery evaporator 19a and a left-side battery evaporator 19b as battery evaporators. Ideally, the right-side battery evaporator 19a and the left-side battery evaporator 19b would each be individually controlled to reach a target degree of superheat, but when one battery expansion valve opens and closes to adjust the degree of superheat of one battery evaporator, the refrigerant flow rate to the other cooling evaporator changes. As a result, the degree of superheat fluctuates, and the other battery expansion valve tries to adjust the degree of superheat to the target, causing control hunting. As a result, the temperatures of the multiple battery evaporators become unstable.

Therefore, it is better to tolerate a certain degree of difference in the degree of superheat of each cooling evaporator and control the opening of each battery expansion valve in conjunction with each other, which will result in more stable control of the cooling evaporators overall.

In consideration of this, in this embodiment, as explained in step S14 (more specifically, step S426), if the difference between the superheat degree SHBR of the refrigerant on the outlet side of the right-side battery evaporator 19a and the superheat degree SHBL of the refrigerant on the outlet side of the left-side battery evaporator 19b is within a reference range (in this embodiment, greater than or equal to -5°C and less than or equal to +5°C), the throttle opening of the right-side battery expansion valve 18a and the left-side battery expansion valve 18b are made the same.

This makes it possible to suppress control hunting of the right-side battery evaporator 19a and the left-side battery evaporator 19b, and stabilize the control of the right-side battery evaporator 19a and the left-side battery evaporator 19b.

In addition, in the vehicle air conditioner 1 of this embodiment, as explained in step S14 (more specifically, steps S423 to S424), the right battery expansion valve 18a and the left battery expansion valve 18b are set to the minimum oil circulation opening Dmin or more. The minimum oil circulation opening Dmin is the minimum throttle opening at which refrigeration oil remaining in at least one of the right battery evaporator 19a and the left battery evaporator 19b can be returned to the compressor 11. This further prevents refrigeration oil from remaining.

In addition, in the vehicle air conditioner 1 of this embodiment, as explained in step S14 (more specifically, steps S423 to S424), when the refrigerant circuit is a battery-only cycle, the minimum oil circulation opening Dmin is set to be larger than when the refrigerant circuit is an air conditioning battery cycle.

As a result, in a battery-only cycle in which refrigeration oil cannot be recovered from the air conditioning evaporator 16, refrigeration oil is more easily recovered from the right-side battery evaporator 19a and the left-side battery evaporator 19b, preventing insufficient recovery of refrigeration oil and resulting in insufficient lubrication of the compressor 11.

In addition, in the vehicle air conditioner 1 of this embodiment, the battery casing 41 houses the battery 70, the right battery evaporator 19a, and the left battery evaporator 19b, and forms a cooling air passage.

As a result, the heat from the battery 70 can reduce the viscosity of the refrigeration oil in the right-side battery evaporator 19a and the left-side battery evaporator 19b, making it easier to recover the refrigeration oil from the right-side battery evaporator 19a and the left-side battery evaporator 19b.

In the vehicle air conditioner 1 of this embodiment, as described in the control process for oil recovery control, oil recovery control is executed when the air conditioning evaporator 16 starts cooling the air for air conditioning.

Therefore, oil recovery control can be completed at an early stage of air conditioning, and oil recovery control is not executed during air conditioning. As a result, after the air conditioning state in the vehicle cabin has stabilized, oil recovery control is not executed, and the temperature and humidity of the blown air blown into the vehicle cabin do not change. In other words, it is possible to prevent a deterioration in the air conditioning feeling of the occupants and a decrease in the anti-fogging ability during air conditioning when the air conditioning state in the vehicle cabin has stabilized.

In addition, in the vehicle air conditioner 1 of this embodiment, during oil recovery control, the battery solenoid valve 14b is opened to allow refrigerant to flow through the right battery evaporator 19a and the left battery evaporator 19b, which are the cooling evaporation sections. This ensures that the refrigeration oil that has accumulated in the right battery evaporator 19a and the left battery evaporator 19b can be returned to the compressor 11.

In addition, in the vehicle air conditioner 1 of this embodiment, in step S306, which is the lower limit value determination unit, the lower limit value for oil recovery is determined to be a value higher than the lower limit value of the rotation speed of the compressor 11 during normal operation. As a result, during oil recovery control, the high-low pressure difference between the high-pressure side refrigerant and the low-pressure side refrigerant of the refrigeration cycle device 10 is increased, and the refrigeration oil remaining in the cycle can be returned to the compressor 11 in a short period of time.

Furthermore, the lower limit value determination unit determines to increase the lower limit value for oil recovery as the outside air temperature Tam decreases. In this way, even if the oil viscosity decreases as the outside air temperature Tam decreases, the high-low pressure difference between the high-pressure side refrigerant and the low-pressure side refrigerant of the refrigeration cycle device 10 can be effectively increased, and the refrigeration oil remaining in the cycle can be returned to the compressor 11 in a short time.

In addition, in the vehicle air conditioner 1 of this embodiment, when refrigerant is flowed into the cooling evaporation section, the increase in the throttle opening per unit time of the right battery expansion valve 18a and the left battery expansion valve 18b is set to be equal to or less than a reference increase. This makes it possible to suppress a sudden decrease in the flow rate of refrigerant flowing into the air conditioning evaporator 16, which is connected in parallel to the cooling evaporation section. Therefore, it is possible to suppress a deterioration in the air conditioning feeling of the occupants and a decrease in the anti-fogging ability.

In addition, in the vehicle air conditioner 1 of this embodiment, the limit opening determination unit determines the limit opening LDop, which is the upper limit of the throttle opening of the right battery expansion valve 18a and the left battery expansion valve 18b, in step S412. Then, when refrigerant is flowed into the cooling evaporation unit, the operation of the right battery expansion valve 18a and the left battery expansion valve 18b is controlled so that the throttle opening of the right battery expansion valve 18a and the left battery expansion valve 18b is equal to or less than the limit opening LDop.

This makes it possible to limit the amount of refrigerant flowing into the cooling evaporation section, making it easier to prevent frosting in the cooling evaporation section. Furthermore, it is also possible to suppress a decrease in the amount of refrigerant flowing into the air conditioning evaporator 16.

Furthermore, the limit opening determination unit increases the limit opening LDop used during oil recovery control as the outside air temperature Tam decreases. This ensures a sufficient refrigerant flow rate and makes it easier to return refrigeration oil remaining in the cycle to the compressor 11 in a short time, even if the oil viscosity decreases as the outside air temperature Tam decreases.

In addition, in the vehicle air conditioner 1 of this embodiment, the time limit determination unit, step S411, determines to increase the time limit LTop as the outside air temperature Tam decreases. This makes it possible to lengthen the execution time of the oil recovery control when the oil viscosity decreases as the outside air temperature Tam decreases. Therefore, the refrigeration oil remaining in the cycle can be effectively returned to the compressor 11.

In addition, in the vehicle air conditioner 1 of this embodiment, in step S303, which is the upper limit value determination unit, the upper limit value of the refrigerant discharge capacity of the compressor 11 during oil recovery control is determined to be a value higher than the upper limit value when switched to the air conditioning only cycle.

As a result, when switching from the air conditioning only cycle to the air conditioning battery cycle in which oil recovery control is executed, the refrigerant discharge capacity of the compressor 11 can be increased to suppress a decrease in the amount of refrigerant flowing into the air conditioning evaporator. This makes it possible to suppress a deterioration in the air conditioning feeling of the occupants and a decrease in the anti-fogging ability.

In addition, in the vehicle air conditioner 1 of this embodiment, oil recovery control is executed when the trip counter Tcnt reaches or exceeds a predetermined reference number KTcnt. This makes it possible to prevent unnecessary oil recovery control from being executed.

In addition, in the vehicle air conditioner 1 of this embodiment, when cooling of the cooling air in the cooling evaporator section starts, execution of oil recovery control is prohibited. This makes it possible to prevent unnecessary oil recovery control from being executed.

In addition, in the vehicle air conditioner 1 of this embodiment, when the temperature of the cooling evaporator falls below the reference frost temperature (KTEB1, KTEB3), execution of oil recovery control is prohibited. This makes it possible to prevent the cooling evaporator from being unnecessarily cooled when frost has formed on the cooling evaporator.

Furthermore, the reference frost temperature (KTEB1) used when oil recovery control is being executed is set to a temperature lower than the reference frost temperature (KTEB3) used when oil recovery control is not being executed. As a result, when oil recovery control is being executed, it is less likely to be determined that frost has formed on the cooling evaporator than when oil recovery control is not being executed.

Here, in the vehicle air conditioner 1 of this embodiment, oil recovery control is executed when the air conditioning evaporator 16 starts cooling the air for air conditioning (i.e., when air conditioning of the vehicle cabin starts). Therefore, when the oil recovery control is executed, it is unlikely that frost has formed on the cooling evaporator. Therefore, the execution of the oil recovery control is prioritized to protect the compressor 11.

In addition, in the vehicle air conditioner 1 of this embodiment, multiple cooling evaporators are provided as the right-side battery evaporator 19a and the left-side battery evaporator 19b. This allows the cooling evaporators to be positioned to effectively utilize the right-side cooling space 43a and the left-side cooling space 43b of the battery pack 40. In other words, the cooling evaporators can be positioned so that they can effectively cool the battery 70.

In addition, in the vehicle air conditioner 1 of this embodiment, multiple cooling flow rate adjustment units are provided as the right battery expansion valve 18a and the left battery expansion valve 18b. The refrigerant flow rates flowing into the right battery evaporator 19a and the left battery evaporator 19b can be adjusted individually. This allows the refrigerant evaporation temperatures in the multiple cooling evaporation units to be adjusted individually, thereby achieving effective cooling of the battery 70.

In addition, in the vehicle air conditioner 1 of this embodiment, the volume of the cooling air that exchanges heat with the refrigerant in the right-side battery evaporator 19a and the left-side battery evaporator 19b is equal to or less than the volume of the air conditioning air that exchanges heat with the refrigerant in the air conditioning evaporator 16. As a result, even if the refrigerant is evaporated to cool the cooling air in the right-side battery evaporator 19a and the left-side battery evaporator 19b, this does not affect the cooling of the air conditioning air in the air conditioning evaporator 16.

In addition, in the vehicle air conditioner 1 of this embodiment, the heat exchange area in the air conditioning evaporator 16 is larger than the combined heat exchange area in the right-side battery evaporator 19a and the left-side battery evaporator 19b. This reduces the amount of refrigerant flowing into the right-side battery evaporator 19a and the left-side battery evaporator 19b, making it easier to stabilize the cooling capacity exerted by the right-side battery evaporator 19a and the left-side battery evaporator 19b.

Other Embodiments
The present invention is not limited to the above-described embodiment, and various modifications can be made as follows without departing from the spirit of the present invention.

The refrigeration cycle device 10 is not limited to the configuration disclosed in the above embodiment. For example, the battery solenoid valve 14b may be eliminated, and the refrigerant passage from the other outlet of the branch 13a to the inlet of the battery side branch 13c may be opened and closed by the full closing function of the right battery expansion valve 18a and the left battery expansion valve 18b. In this case, it is desirable to ensure sufficient responsiveness in the operation of the right battery expansion valve 18a and the left battery expansion valve 18b.

In the above embodiment, for example, the throttle opening of the right-side battery expansion valve 18a is operated based on a predetermined control characteristic diagram stored in the air conditioning control device 50, but this is not limited to the above. For example, the throttle opening of the right-side battery expansion valve 18a may be changed using a feedback control method based on the superheat difference obtained by subtracting the target cooling side superheat SHBO from the right-side superheat SHBR.

In addition, in the above embodiment, an example was described in which two cooling evaporation sections, the right-side battery evaporator 19a and the left-side battery evaporator 19b, were used, but the number of cooling evaporation sections is not limited.

In the above embodiment, an example was described in which refrigerant was simultaneously introduced into both the right-side battery evaporator 19a and the left-side battery evaporator 19b when cooling the battery 70. However, in low outside air temperatures, for example, refrigerant may be introduced alternately into the right-side battery evaporator 19a and the left-side battery evaporator 19b.

In the above embodiment, an example was described in which R1234yf was used as the refrigerant for the refrigeration cycle device 10, but the refrigerant is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be used. Alternatively, a mixed refrigerant made by mixing multiple refrigerants among these may be used.

The heat medium circuit 20 is not limited to the configuration disclosed in the above embodiment. For example, in the above embodiment, an example was described in which an ethylene glycol aqueous solution was used as the heat medium, but the present invention is not limited to this. As the heat medium, dimethylpolysiloxane, a solution containing nanofluid, antifreeze, a water-based liquid refrigerant containing alcohol, a liquid medium containing oil, etc. may also be used.

Furthermore, the battery pack 40 is not limited to the configuration disclosed in the above embodiment. In the above embodiment, an example was described in which the battery 70 is cooled by circulating cooling air cooled in the cooling evaporation section within the battery casing 41 of the battery pack 40, but the present invention is not limited to this.

For example, a refrigerant-heat medium heat exchanger is provided that exchanges heat between the low-pressure refrigerant flowing out of the cooling flow rate adjustment unit and the low-temperature heat medium to cool the low-temperature heat medium. The low-temperature heat medium cooled in the refrigerant-heat medium heat exchanger may then be allowed to flow into a cooling water passage formed in contact with the battery 70 to cool the battery 70.

In the above embodiment, the battery 70 is described as an example of the object to be cooled, but the object to be cooled is not limited to this. The object to be cooled may be, for example, an in-vehicle device that generates heat during operation, such as an inverter, a motor generator, a power control unit (a so-called PCU), a control device for an advanced driver assistance system (a so-called ADAS), etc.

Furthermore, the air conditioning control device 50 is not limited to the configuration disclosed in the above embodiment. For example, the battery temperature sensor 59 may be connected to the vehicle control device 80. The air conditioning control device 50 may then read the battery temperature TB input to the vehicle control device 80 and use it for various controls.

The control by the air conditioning control device 50 is not limited to that disclosed in the above embodiment. For example, in the above steps S406 and S407, an example was described in which 5% was used as the opening degree that allows the refrigerant to pass through the cooling pressure reduction sections 18a and 18b, but this is not limited. As long as the opening degree allows the refrigerant to pass through, it may be greater or smaller than 5%.

In the above embodiment, in step S413, an example was described in which the reference increase amount was an increase per second of 0.1% of the maximum opening, but this is not limited to this. If a sudden decrease in the refrigerant flowing into the air conditioning evaporator 16 can be suppressed, the increase amount may be set to 0.1% or less.

Furthermore, as in step S413 described above, the reference increase amount may be changed. That is, the reference increase amount may be 0.1% until the switching elapsed time Top reaches the time limit LTop, and the reference increase amount may be changed to 0% after the time limit LTop. In this case, the reference increase amount may be changed in a stepwise manner or continuously.

In the above embodiment, an example is described in which the time limit LTop is determined in step S411 according to the outside air temperature Tam, and the opening limit LDop is determined in step S412 according to the outside air temperature Tam, but this is not limiting. For example, the time limit LTop may be a fixed value (e.g., 30 seconds), and the opening limit LDop may be a fixed value (e.g., 5%).

In addition, in step S404 of the above embodiment, an example was described in which the level of the anti-fogging request was determined using the outside air temperature Tam, but this is not limited to this. The level of the anti-fogging request may also be determined using the humidity near the window RHW detected by the humidity sensor 59a.

In the above embodiment, an example has been described in which the control process for oil recovery control shown in FIG. 27 is executed in parallel with the control process of the main routine, but this is not limiting. For example, when the process proceeds to step S806 and it is determined that oil recovery control is to be prohibited, the control process for oil recovery control may be stopped until the next startup of the vehicle system.

In addition, in the above embodiment, no mention is made of the operation of the right-side cooling blower 42a and the left-side cooling blower 42b when the oil recovery control is executed in step S805, but in the oil recovery control, the right-side cooling blower 42a and the left-side cooling blower 42b may be operated in the same manner as in normal operation, or may be stopped. Furthermore, in the oil recovery control, the compressor 11 may be operated continuously or intermittently.

The reference number KTcnt used in step S802 in the above embodiment may be determined in consideration of the ease with which refrigeration oil remains in the cycle depending on the system configuration. Furthermore, when it is determined in step S803 that the battery cooling operation is permitted, the trip counter Tcnt may be reset.

In addition, in the above-described embodiment, the right-side battery expansion valve 18a is both a cooling pressure reducing section and a cooling flow rate adjusting section that adjusts the refrigerant flow rate flowing into the right-side battery evaporator 19a, but the cooling flow rate adjusting section that adjusts the refrigerant flow rate flowing into the right-side battery evaporator 19a may be provided separately from the right-side battery expansion valve 18a.

Similarly, the left battery expansion valve 18b is both a cooling pressure reducing section and a cooling flow rate adjusting section that adjusts the refrigerant flow rate flowing into the left battery evaporator 19b, but the cooling flow rate adjusting section that adjusts the refrigerant flow rate flowing into the left battery evaporator 19b may be provided separately from the left battery expansion valve 18b.

11 Compressor 12 Radiator (condenser)
13a Branching section 13b Junction section 14b Opening/closing section (battery solenoid valve)
15 Air conditioning pressure reducing section (air conditioning expansion valve)
16 Air conditioning evaporator (air conditioning evaporator)
18a, 18b Cooling flow rate adjustment unit (right battery expansion valve, left battery expansion valve)
19a, 19b Cooling evaporation section (evaporator for right battery, evaporator for left battery)
460 Cooling flow passage section

Claims (20)

A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) that radiates heat from the refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) that reduces the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates the refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
A cooling flow path portion (460) through which the refrigerant flows from the branch portion to the cooling pressure reducing portion;
An opening/closing portion (14b) for opening and closing the cooling flow passage portion;
a control unit (50) that controls the operation of the cooling pressure reducing unit and the opening and closing unit,
When there is no request to cool the object to be cooled, the control unit closes the opening/closing unit and sets the cooling pressure reducing unit to an opening degree that allows the refrigerant to pass through ,
The refrigerant is mixed with refrigerating machine oil,
When starting to cool the air-conditioning air in the air-conditioning evaporator, an oil recovery control is executed to return the refrigeration oil remaining in at least one of the air-conditioning evaporator and the cooling evaporator to the compressor,
a cooling flow rate adjusting section (18a, 18b) for adjusting a flow rate of the refrigerant flowing into the cooling evaporation section;
a cooling flow rate control unit (50a) for controlling the operation of the cooling flow rate adjustment unit;
the cooling flow rate control unit controls the operation of the cooling flow rate adjustment unit so that an increase in the throttle opening of the cooling flow rate adjustment unit per unit time is equal to or less than a predetermined reference increase amount when the refrigerant is caused to flow into the cooling evaporation unit;
A limiting opening determination unit (S412) is provided for determining a limiting opening (LDop) which is an upper limit of the throttle opening of the cooling flow rate adjustment unit,
The cooling flow rate control unit controls the operation of the cooling flow rate adjustment unit so that the throttle opening of the cooling flow rate adjustment unit is equal to or less than the limit opening when the refrigerant is flowed into the cooling evaporation unit . A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) that radiates heat from the refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) that reduces the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates the refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
A cooling flow path portion (460) through which the refrigerant flows from the branch portion to the cooling pressure reducing portion;
An opening/closing portion (14b) for opening and closing the cooling flow passage portion;
a control unit (50) that controls the operation of the cooling pressure reducing unit and the opening and closing unit,
When there is no request to cool the object to be cooled, the control unit closes the opening/closing unit and sets the cooling pressure reducing unit to an opening degree that allows the refrigerant to pass through ,
The refrigerant is mixed with refrigerating machine oil,
When starting to cool the air-conditioning air in the air-conditioning evaporator, an oil recovery control is executed to return the refrigeration oil remaining in at least one of the air-conditioning evaporator and the cooling evaporator to the compressor,
An upper limit value determination unit (S303) that determines an upper limit value of the refrigerant discharge capacity of the compressor,
The upper limit value determination unit determines the upper limit value when the oil recovery control is executed to a value higher than the upper limit value during an operating mode in which the refrigerant is allowed to flow into the air conditioning evaporator section and the refrigerant is prohibited from flowing into the cooling evaporator section . A compressor (11) that draws in, compresses, and discharges a refrigerant;
a radiator (12) that radiates heat from the refrigerant discharged from the compressor;
an air conditioning pressure reducing section (15) that reduces the pressure of the refrigerant whose heat has been radiated by the radiator;
an air conditioning evaporation section (16) that evaporates the refrigerant decompressed in the air conditioning decompression section in order to cool the air for air conditioning to be blown into the vehicle interior;
a cooling pressure reducing section (18a, 18b) arranged in parallel with the air conditioning pressure reducing section in the flow of the refrigerant and reducing the pressure of the refrigerant whose heat has been radiated by the radiator;
a cooling evaporation section (19a, 19b) for evaporating the refrigerant decompressed in the cooling decompression section to cool an object to be cooled (70);
a branching section (13a) for branching the refrigerant flowing from the radiator to the air conditioning pressure reducing section to the cooling pressure reducing section;
a confluence section (13b) for confluence of the refrigerant flowing from the cooling evaporator section with the refrigerant flowing from the air conditioning evaporator section to the compressor;
A cooling flow path portion (460) through which the refrigerant flows from the branch portion to the cooling pressure reducing portion;
An opening/closing portion (14b) for opening and closing the cooling flow passage portion;
A control unit (50) that controls the operation of the cooling pressure reducing unit and the opening and closing unit,
When there is no request to cool the object to be cooled, the control unit closes the opening/closing unit and sets the cooling pressure reducing unit to an opening degree that allows the refrigerant to pass through ,
The refrigerant is mixed with refrigerating machine oil,
When starting to cool the air-conditioning air in the air-conditioning evaporator, an oil recovery control is executed to return the refrigeration oil remaining in at least one of the air-conditioning evaporator and the cooling evaporator to the compressor,
The oil recovery control is prohibited when the temperature (TEBR, TEBL) of the cooling evaporation section becomes equal to or lower than a predetermined reference frosting temperature (KTEB1, KTEB3),
The reference frost temperature (KTEB1) used when the oil recovery control is being executed is set to a temperature lower than the reference frost temperature (KTEB3) used when the oil recovery control is not being executed. a casing (41) that houses the object to be cooled, the cooling evaporation section, and the cooling pressure reduction section;
4. The vehicle air conditioner according to claim 1, wherein the opening/closing section is disposed closer to the branch section than the cooling pressure reducing section is. 4. The vehicle air conditioner according to claim 1, wherein the oil recovery control comprises circulating the refrigerant through the cooling evaporator portion. A lower limit value determination unit (S306) that determines a lower limit value of the refrigerant discharge capacity of the compressor,
The vehicle air conditioner according to claim 5 , wherein the lower limit value determining unit determines the lower limit value during execution of the oil recovery control to be a value higher than the lower limit value during normal operation when the oil recovery control is not being executed. The vehicle air conditioning system according to claim 6 , wherein the lower limit value determining unit increases the lower limit value as the outside air temperature (Tam) decreases. a cooling flow rate adjusting section (18a, 18b) for adjusting a flow rate of the refrigerant flowing into the cooling evaporation section;
a cooling flow rate control unit (50a) for controlling the operation of the cooling flow rate adjustment unit;
4. The vehicle air conditioning system according to claim 2, wherein the cooling flow rate control unit controls the operation of the cooling flow rate adjustment unit so that an increase in the throttle opening of the cooling flow rate adjustment unit per unit time is equal to or less than a predetermined reference increase amount when the refrigerant is caused to flow into the cooling evaporation unit. A limiting opening determination unit (S412) is provided for determining a limiting opening (LDop) which is an upper limit of the throttle opening of the cooling flow rate adjustment unit,
9. The vehicle air conditioning system according to claim 8, wherein the cooling flow rate control unit controls the operation of the cooling flow rate adjustment unit so that a throttle opening of the cooling flow rate adjustment unit is equal to or less than the limit opening when the refrigerant is caused to flow into the cooling evaporation unit. The vehicle air conditioning system according to claim 9 , wherein the opening limit determination unit increases the opening limit used when the oil recovery control is performed in accordance with a decrease in an outside air temperature (Tam). A time limit determination unit (S411) for determining a time limit (LTop) for executing the oil recovery control,
11. The vehicle air conditioner according to claim 1, wherein the time limit determination unit increases the time limit as an outside air temperature (Tam) decreases. An upper limit value determination unit (S303) that determines an upper limit value of the refrigerant discharge capacity of the compressor,
4. The vehicle air conditioning system according to claim 1, wherein the upper limit value determination unit determines the upper limit value during execution of the oil recovery control to be a value higher than the upper limit value during an operating mode in which the refrigerant is allowed to flow into the air conditioning evaporator and the refrigerant is prohibited from flowing into the cooling evaporator. When one driving session is defined as the period from starting up the vehicle system to stopping it,
13. The air conditioner for a vehicle according to claim 1, wherein execution of the oil recovery control is permitted when the vehicle has been driven a predetermined reference number of times (KTcnt) or more. 14. The vehicle air conditioning system according to claim 1, wherein the oil recovery control is prohibited when cooling of the object to be cooled is started. 3. The vehicle air conditioner according to claim 1, wherein the oil recovery control is prohibited when a temperature (TEBR, TEBL) of the cooling evaporator portion becomes equal to or lower than a predetermined reference frosting temperature (KTEB1, KTEB3). The vehicle air conditioning device according to claim 15, wherein the reference frost temperature (KTEB1) used when the oil recovery control is being executed is set to a temperature lower than the reference frost temperature (KTEB3) used when the oil recovery control is not being executed. 17. The vehicle air conditioner according to claim 1, wherein a plurality of the cooling evaporators are provided. Further, a cooling flow rate adjusting section (18a, 18b) is provided for adjusting the flow rate of the refrigerant flowing into the cooling evaporation section,
18. The vehicle air conditioner according to claim 17 , wherein a plurality of the cooling flow rate adjusting sections are provided so that the flow rates of the refrigerant flowing into the respective cooling evaporation sections can be individually adjusted. The air conditioning evaporation section is an air conditioning evaporator (16) that exchanges heat between the refrigerant and the air for air conditioning,
The cooling evaporation section is a cooling evaporator (19a, 19b) that exchanges heat between the refrigerant and cooling air blown onto the object to be cooled,
19. The vehicle air conditioning system according to claim 1, wherein the volume of the cooling air that exchanges heat with the refrigerant in the cooling evaporator is equal to or less than the volume of the air conditioning air that exchanges heat with the refrigerant in the air conditioning evaporator. 20. The vehicle air conditioner according to claim 19 , wherein a heat exchange area between the refrigerant and the air-conditioning air in the air-conditioning evaporator is larger than a heat exchange area between the refrigerant and the cooling air in the cooling evaporator.

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